It's elementary – just lie back and enjoy

The second series of 'Sherlock' gets us off to a promising start, and there's always more 'Downton' to look forward to

Zooey Deschanel, in Channel 4's latest sitcom import New Girl, hovers between adorable and irksome (FOX)

Broadcasters aren't hanging about: the year's highlights begin, well, today.

Let the battle for ratings – and one's inner tussle between going to the gym/staying on the sofa eating Quality Street by the rustling fistful – begin! Sherlock returns on BBC1 this very night, with Benedict Cumberbatch and Martin Freeman dusting off the classic double act, and that long swooshy coat, for three new episodes. Competition, however, comes from Sky 1's starry new adaptation of Treasure Island – Elijah Wood, Donald Sutherland, Shirley Henderson and many others are led by Eddie Izzard as Long John Silver. Tomorrow, ITV weighs in with its "young Inspector Morse" prequel, Endeavour: warmly welcome or sacrilegious, depending on your point of view.

Similarly divisive could be Channel 4's acquisition, perky sit-com New Girl (from 6 Jan), starring Zooey Deschanel, the indie darling who treads a fine line between adorable and irksome. Channel 4 is also riding The Great British Bake Off wave, with The Fabulous Baker Brothers (from 4 Jan) – expect close-ups of arms toned from kneading and eyes more twinkly than current buns as we follow Tom and Henry, the "artisan" bakers. A more serious January offering from the same stable is Death Row Stories. Idiosyncratic German director Werner Herzog spent a year talking to inmates awaiting execution; an expansion of his film Into the Abyss, it's likely to be grim, but insightful.

March sees, finally, the arrival of season five of Mad Men on Sky Atlantic. Set to "record series" and say no more. The Hour, which turned out to be nothing like Mad Men but which was slow-burningly enjoyable, will be back on BBC2, with added Peter Capaldi, which can only be a good thing. And The X Factor better watch out, when The Voice arrives on the beeb in March: supposedly about vocal talent, not looks, but it's likely the same old sob stories and trumped up rivalries will feature. However, the choice of judges – Tom Jones, Jessie J, and will.i.am – may make it hard to resist.

Love Life arrives on BBC1 in the spring. Five new modern love stories, starring the likes of David Tennant, Billie Piper and Jane Horrocks, they're packed with affairs, lesbian urges and love at first sight. And BBC2 gets deliciously highbrow in April with Shakespeare's History plays, from Richard II to Henry V. It's part of the Cultural Olympiad – and of course, in 2012, the BBC will rightly be chock-a-block with Olympic sporting coverage. But given the Henriad is directed by theatrical heavyweights Rupert Goold, Richard Eyre and Thea Sharrock, and stars Ben Whishaw, Rory Kinnear, Patrick Stewart, Tom Hiddleston and Simon Russell Beale, it should prove welcome for those who prefer the muse of fire to the Olympic flame.

Sky Atlantic gears up with its first original commission, Hit and Miss, in May. Scripted by Paul Abbott (Shameless, when it was still good), it really does sound original: Chloe Sevigny stars as a contract killer with a secret: she's a transgender woman who discovers she fathered a son. Also on Sky Atlantic is Veep – The Thick of It US, essentially. Airing in summer, Armando Iannucci's satirical peer into the corridors of power in Washington will hopefully be as sharp and expletive-ridden as its Brit predecessor (luckily Chris Morris is directing, which should keep it caustic).

Later in 2012 there's Dancing on the Edge, Stephen Poliakoff's first major TV series, about black jazz musicians in 1930s London, and The Girl, which explores Hitchcock's obsession with Tippi Hedren (both BBC2). The latter is drawn from interviews with the actress herself, who'll be played by Sienna Miller, alongside Toby Jones as the master of suspense. They'll also be reliably cosy viewing when Downton Abbey returns in the autumn on ITV.

Finally, could it be the year BBC3 reels you in? Come autumn, there'll be a new series of Him & Her, and the arrival of The Revolution Will Be Televised. Heydon Prowse and Jolyon Rubinstein make the transition from internet vids on website Don't Panic, but promise to continue to lampoon vapid celebs, weaselly politicians and greedy bankers. Jack Whitehall, after a star turn in Fresh Meat, graduates to playing a terrible teacher in Bad Education. Plus, the channel has a sex season, from the documentaries Coming Out Diaries and Undressed – about women who work in the lap-dancing industry – to a CGI anatomical exploration of How Sex Works. Oh come on, you know you'll be watching: who's not interested in "the science of lust and the mechanics of sex"...?

Watch out for...

She was plucked from drama school to star in Sky 1's The Runaways last year – which put Joanna Vanderham (right) firmly on the "rising star" list. Catch her over the coming year in ITV's Above Suspicion, the BBC's Dancing on the Edge and with Steve Coogan and Julianne Moore in a film of Henry James's What Maisie Knew.