If you're offering credit card details, ensure that the site you're using has a secure server. A quick check is to look for a little padlock icon in the bottom of your browser.
Don't give out information that isn't necessary to make a purchase. Reputable sites will not insist that you do.
Make a note of promised delivery dates, and also take note of a contact phone number and order number. This is vital if something goes wrong and you need to chase up your order.
Print off the page showing the goods you've ordered for future reference.
If you're uncomfortable giving card details, you can usually order by phone or email instead.
Aimed at women, www.handbag.com's practical guide to successful online Christmas shopping offers advice and tips, and demystifies technical terms, as well as identifying the top 10 shopping sites this year.
www.icircle.co.uk, the online women's channel from Freeserve, has a Christmas and millennium holiday helper, which is an interactive guide to surviving the holiday season. You can also arrange to send a Christmas wish-list to your partner anonymously, and children can send a list to Santa. They'll get a reply and the list is sent to you.
www.happychristmas.com will email your Christmas cards so you don't have to post real ones. Think of the savings on stamps!