Nicholas Coleridge, managing director of the Conde Nast publishing empire, is clever, creative and a brilliant business man, mostly because he is his magazines. He lives in a world taken directly from the pages of his sumptuous periodicals.

So, to Vogue House, in Hanover Square, home of Conde Nast and all their gloriously glossy magazines - Vogue, Tatler, World of Interiors, Vanity Fair, Traveller, House and Garden, GQ, GQ Active and Brides and Setting Up Home, which, I imagine, is immensely useful if you're a bride setting up home.

Past the big security man, up in the lift with two young women in black who may or may not be called Pippa. They get out at World of Interiors. ("Second Floor. World of Interiors. Mole Suede Cushions. Chinese Antiques. Tufenkian Tibetan Carpets. Handmade wallpaper, a snip at pounds 7,500 a roll...") I continue to the fourth floor, then go along a corridor decorated from one end to the other with framed shopping bags - Gucci, Chanel, Hermes, Armani, Versace, Tiffany, Cartier but, mysteriously, no Whatever She Wants, a reasonable establishment on the Holloway Road which, I have found, offers terribly good value so long as you don't mind totally unfashionable rubbish cheaply tailored from 100 per cent polyester.

Finally, I make it to Nicholas Coleridge's office. Nicholas Coleridge, 40, is managing director of Conde Nast's nine titles in the UK and, thus, very much in charge of what we read, if not in our own homes, then at least down the hairdressers. Nicholas's office is huge, overlooks the square, and has as its centrepiece, his desk - a massive, glass Corbusier job with no drawers because, he explains, "no drawers means no clutter. There's no place to stuff anything away and just forget about it." He adds that the trouble with desk drawers is that, no matter how hard you try, the top one inevitably fills with old paperclips and pens without tops. Obviously, old paper-clips and pens without tops are not encouraged at Vogue House.

Nicholas is very spare. Gaunt, even. You can see the bones of his skull working under his skin. Actually, he looks rather like a sucked-out Kelsey Grammar from Frasier. He is wonderfully dapper, though. Handmade leather shoes. Pink shirt. Braces. Twinkling cufflinks. Starry tie made for him by his personal tailor. I have tried my best. I am at least wearing clean jeans as opposed to yesterday's jeans with a sock caught up one leg. But I can instantly see it's not good enough. I apologise. I say I'll quite understand if I'm fined on my way out. Nicholas cries: "Oh, but you look lovely. Lovely!" Complete rubbish, of course. But from then on, I am absolute putty in his hands. I even say to him at one point: "Mr Coleridge, if you would like me to island hop in the Caribbean for Conde Nast Traveller, you only have to say the word." He says: "Thank you. I will. Yes. Um."

Anyway, a charming man, with the wonderfully smooth manners of someone who's been to Eton and hasn't ended up a mad drug addict. Plus, he's said to be pretty good at what he does, too. All the titles have thrived under him. Vogue has even just passed the 200,000 mark for the first time ever. Tatler has been revived. The two newest titles - Traveller and GQ Active - have got off to good starts. I'm sure Nicholas is clever and creative and a brilliant businessman and all that, but mostly I reckon he is successful because he is his magazines. He lives a very House and Garden, Vogue, World of Interiors, Tatler, four-page-spread-on-Mauritius, Conde Nast sort of life, so understands the market perfectly. He recently bought an pounds 8,000 marble-topped table. "I saw it and liked it but hummed and hawed for about a month. The shop said they'd keep it for me. Then I went in and they said they had two other people interested, so could I please make up my mind? They showed me the other two people's business cards. One was Ralph Lauren. The other was Jacob Rothschild. So of course I bought the table immediately." Nicholas is saying it's all right to be a bit of a snob. And that, of course, is what most Conde Nast readers want to read. Plus they're never interested in self-assembly.

But he's not only big in magazines. He also writes books, both fiction and non-fiction, and seems to do pretty well at this, too. His book on press barons, Paper Tigers, was a best seller, as was his first novel, Fashion Conspiracy, "which is currently number one in Korea". His latest novel, With Friends Like These, comes out in paperback today (Orion, pounds 5.99). It's a thriller set in the magazine world. It's not too bad, so long as you like your heroines to come dressed in Lacroix and Katchinsky diamonds, whatever they may be. Usefully, you can tell who's working class because they say "guv'nor" a lot. Anyway, what he is most looking forward to is the accompanying advertising campaign. "It's going to be advertised on the side of London buses." He has a list of the routes - "the 137, the 345...". No, none run near Vogue House, which is only ever fed by taxis, but no matter. "I'm going on a little tour tonight, to see if I can spot any."

He can be quite touchingly vain. Recently, he wrote a piece for the Daily Telegraph in which he claimed Tony Blair could be his twin. "He eats in the same kinds of places as me and even chooses the same kind of fish and polenta dishes off the menu. The Blairs go on holiday to the same part of Tuscany we (he and his wife, Georgia) go to and their children wear Polo Ralph Lauren shirts, just like our children do." He stands by this comparison. "The other day, Georgia and I were in a restaurant, and the Blairs were at the next table, and it struck me that Georgia looked very much like Cherie, only much prettier."

I wonder, what comes first with him, the books or the magazines? The mags, definitely, he cries. The books are just a hobby, something he does on Saturday mornings. He has loved magazines, he says, ever since he was 14 or so and ill at home and his mother, loaned him her copy of Harpers and Queen. He loved everything about it. The smell. The feel. The content, that mixture of the wholly trivial and really rather serious. He is still very in love with magazines. He likes to hold the pages up sideways to the light because, as he explains rapturously, "that way you can actually see the ink sitting on the page". Which magazines would he like to bring into the Conde Nast stable if he could? Marie Claire, he says. And Country Life. But, no, he doesn't have his eye on my own personal favourite, Hello!. "I don't think it's really us. I see they did Gloria Hunniford again this week. Tell me, how many yellow jackets do you think Gloria Hunniford has?"

He asks, would I like a floor-by-floor tour of some of the Conde Nast titles? You bet, I cry. Vogue first? Yes! Yes! What are we waiting for. Let's go.

Vogue. Fifth Floor. Circulation: 200,113. Unfortunately, there is no planning meeting going on, which is a shame, because it has long been my ambition to go into a Vogue planning meeting, sigh significantly, and say: "I'm thinking lace. More, I'm thinking Kate Winslett and lace." And then go out for lunch.

Instead, the place is full of more Pippas in black, either on the phone or sorting though rows of pink frocks or scurrying around carrying Manolo Blahnik peep-toes and crying, "aren't they gorge?". I am introduced to the editor, Alexandra Shulman. What's with this black, I ask. "I don't know. There is no rule. It just happens," she says. Actually, she's in a red cardi. She's not a Pippa anymore.

Nicholas, probably, used to be the male version of a Pippa. His father is a former chairman of Lloyds. At an early age, Nicholas was squeezed into the russet knickerbockers of Hill House, the Sloane's school in Chelsea, before being despatched to a prep school in Sussex and then Eton. I think it would be safe to say Mr Coleridge has never knowingly shoplifted or regarded being taken to tea at The Golden Egg as something of a treat.

He enjoyed Eton enormously, yes. "It had a sophisticated atmosphere, and wasn't too far from London." He contributed to the Eton College Chronicle - then run by Charles Moore, now the editor of the Daily Telegraph - and got his first piece published in Harpers at 15, when he sent in a handwritten piece on tips for surviving teenage parties. ("Don't invite too many old flames or they'll ignite.")

From Eton he went to Cambridge to study theology. No, he wasn't especially interested in theology, but it was easy to get in if you pretended to be. He never took his finals, though, because a back injury meant he was in hospital at the time he should have been taking them. He could have gone back the following year, but didn't bother. By this time, he was fired up and at Tatler, an associate editor at 22. Quick work.

Tatler. Third Floor. Circulation: 87,341. And a Candida. I overhear someone say, "Tea, Candida?" So not all Pippas, no. Nicholas has an especially soft spot for Tatler, because it's where he truly got started. It was in the days before it was owned by Conde Nast and quite poor. "I would ring up book publishers, particularly publishers of expensive, illustrated books like Thames and Hudson, and pretend we were doing a big supplement on, say, beautiful houses in Tuscany. They would bike round the books at their expense, then I'd go in a taxi to a second-hand bookshop called D Levin on Grape Street where I'd sell them for cash. Then, I'd bring back the pounds 400 or so and hand it to Tina Brown and she would hand it to Julian Barnes, who was then the restaurant critic. And he would then go to Langhams and write a take on how Tatler readers would find Langhams somehow not up to scratch." This may be the Eton boys equivalent to shoplifting.

Yes, of course he was and is a big admirer of Tina, who turned Tatler from an idolising, social register into something much wittier. Tatler has had its slumps since. The late Eighties, for example, was a bad time because, he says, the title became contemptuous of its own readers. "You know, the interviews were all negative, knocking pieces." It's now back on course, though. You can send up your readers, he says. They don't mind a bit of that. But you can't despise them. I say the trick is to have a very posh editor, isn't it? Because she can get away with referring to the Marsden Smedleys as the "Farting Deadlies" (page 129 of the current issue) whereas an outsider can't. You know, it's rather like Jewish jokes. It's all right to tell them if you're a Jew, but not if you're not. He disagrees. "Jane Proctor (the current editor) is not an aristocrat. But she does understand new money and the aspirations of new money.'

Brides and Setting Up Home. Sixth Floor. Circulation: 63, 543. The biggest selling title in the brides market, with a great room stuffed with wedding dresses and an editor, Sandra Boler, who finds this a very tiring time of year. "All the girls at Conde Nast seem to get engaged at Christmas, and they all want to come in and show me their rings and discuss it."

Anyway, what about Nicholas when it comes to brides and setting up home? Well, he first met Georgia Metcalfe in 1985, by which time he'd moved from Tatler to the deputy editorship of Harpers and Queen. She'd come into the magazine for two days work experience before going up to Oxford to study PPE. Nicholas met her on her second day. He was looking forward to seeing her on her third day, and was terribly disappointed when she didn't come in, and even further disappointed when he was told she wouldn't be coming in again. "I just liked how she looked and what she was." He traced her parents address and phone number, and called them. "Sorry," they said. "Georgia's just gone off to India." Nicholas went off to India himself, where he contrived to bump into her in the street in Jaipur. Yes, she was rather shocked. He kissed her in a rickshaw. They married four years later, when she finished her degree. She wore an Alistair Blair wedding dress. They honeymooned in France and picnicked using the picnic basket Tina Brown and Harold Evans gave them as a wedding present. "An astonishing wicker thing with, inside, a dozen Meissen plates and numerous silver plate corkscrews." They now live in a whacking great house in Notting Hill and have three children aged six and under, all with very Conde Nast names - Lee, Dwayne and Tracie. No, only joking. They're called Alexander, Freddie and Sophie. Yes, they all attend public schools, "although I have nothing against state schools. I'd send my children there if I didn't have the money." Did he have a lot of girlfriends before Georgia? "Several but not a lot, no. I wasn't like James Brown."

GQ. First Floor. Circulation:135,563. The GQ floor is not like the other floors. There are fag butts on the landing and crates of beer inside the entrance and a blow-up doll on one of the shelves. James Brown was the editor of Loaded until Nicholas brought him here, to toughen up their only men's title. "Yes, it was a risk, but a calculated risk. James is very clever and now has a very nice wife." According to Private Eye, James spends days on the sofa in his office recovering from hangovers while being sick in his wastepaper bin. Nicholas says these stories are wholly untrue. "James told me he had to lie down on his sofa recently because he had flu." I am briefly introduced to James, who turns to Coleridge, and says, "Nick, I went into the Loaded office the other night. It was a complete tip. I wonder how they ever get any work done there." James might be becoming a sort of Conde Nast person himself.

Mini-tour over, it's back to Nicholas's office. He's going out tonight. First, there's a launch party for a new L'Oreal product then it's another party for a Tatler travel supplement. No, he does not find schmmoozing advertisers tiresome. "There are worst things than coming through the door of a shop in Bond Street and being given a drink and something to eat." However, before he goes, he has a few matters to deal with on his glass-topped desk, so... I am charmingly man-handled out of his office, back along that corridor - no Bhs bag either, I note - and into the lift. "I'm quite serious about the Caribbean offer," I manage to cry before the doors close. "I know," I think he might have sighed.