Ten years after being formed in 1995, eBay has become the world's leading online marketplace for all sorts of goods. At any given time, 29 million items are available worldwide on eBay, with more than 3.5 million new items added every day and $1,000 worth of merchandise sold every second. The online auction site has 135 million registered users in 32 international markets, and more than 430,000 people in the United States alone make a full- or part-time living on eBay.

If you think eBay is just about bobblehead dolls and Pez dispensers, think again. While $2.2 billion worth of goods in collectibles were sold on eBay in 2004, antiques and collectibles ranked only No. 6 among eBay's sales categories. The five highest were: automobiles and auto supplies ($11.1 billion); consumer electronics ($3-5 billion); computers ($3.0 billion); clothes and accessories ($2.9 billion); and books, movies and music ($2.4 billion).

Real people are making big bucks on eBay--and thousands have even reached PowerSeller status by maintaining at least $1,000 per month in sales for three consecutive months. Case in point: Angle Cash, 37, a stay-at-home mom who started selling on eBay nearly six years ago because it was "something I could do and watch the kids at the same time." Today, her Kennesaw, Georgia, company, Cashco1000 Inc. (www. cashco1000.com), sells thousands of home-decoration and other items each month on eBay and expects to break $500,000 in sales on eBay this year.

Even owners of existing businesses have found success on eBay by using it as an adjunct to their brick-and-mortar operations. Dan Morphy, 33, runs the Adamstown Antique Gallery (www. aagal.com), a 10,000-square-foot antiques mall in Denver, Pennsylvania. After a few successful eBay auctions, he started offering the antiques vendors who rent space in his gallery the opportunity to sell five items a month on eBay, at no charge other than out-of-pocket expenses. Within two years, Morphy not only had a full gallery of dealers, but was also listing 700 pieces a month and had exceeded $2.5 million in eBay sales.

If you dream of building your own eBay business, it's easier than you think. We've distilled what you need to know into five basic steps.

Step 1: Register Your Business