I Want to Buy Something
If you're registered, go ahead! Adam Ginsberg, eBay PowerSeller and author of How to Buy, Sell and Profit on eBay (Harper Collins) recommends buying something as soon as you register as a member of eBay. He says that a quick initial buy does two things: It familiarizes you with the eBay site navigation, and it is a fast way to increase your feedback score.
If you're not quite ready to shop and have registered as a new member, read Buy an Item. Keep in mind that you will get the best deals on eBay by doing research — for example, checking what similar items are selling for, researching what similar items have sold for, and reviewing the seller's feedback ratings.