So many books, so little time--and even less space to store them all. That is what motivated Steve Weber to start his business selling used books on eBay. But what started out as a way of avoiding clutter at home--and making a little extra cash--has since turned into a successful online business selling books.

From the random items on his bookshelf, Weber (eBay User ID: weber-books), of Falls Church, Virginia, began acquiring books from estate sales and library sales, looking for quirky items with unique appeal. He once found a $2 copy of the cult classic How I Turned $1,000 Into $5 Million in Real Estate in My Spare Time by William Nickerson and sold it online for $130.

Today, Weber, 46, buys his stock from remainder wholesalers, which are businesses that buy unsold new books sent back from bookstores to the publisher. His inventory is now about 75 percent new books, which has boosted his profits tremendously. "[Selling new books] is a different animal, because it allows you to have higher volume and more sales," says Weber, who describes his experience in his own self-published book, The Home-Based Bookstore.

Going from castoff bargains to online retailing required a shift in Weber's business model, one that all eBay entrepreneurs will face once they're ready for the leap into buying in bulk. "Wholesalers want a relationship with someone they feel is operating a real business," Weber says. "They want to see a business license, a state resale certificate and minimum orders in the hundreds."

Building your business on eBay with more established suppliers can diversify your offerings and stabilize your operation. Making your first wholesale connection can be as easy as flipping through the Yellow Pages to Wholesaler and identifying the companies that specialize in the products you want to sell. Other terms to use include Liquidators, Job Lot Traders or Closeout Distributors. You can also find these sources with searches on the internet or on eBay itself.

Some eBay sellers rely on drop-shippers for supply, though some eBay experts say this reduces profit margins too much to be a viable long-term option. But some eBay sellers consider it worth paying for a service where another company buys and stores the product, then does all the packaging and shipping. Trade shows and merchandise marts provide another way to link up with suppliers.

Nancy Baughman, co-founder with her husband, Daren, both 43, of eBiz Auctions (eBay User ID: ebizauctions) in Raleigh, North Carolina, found another way to source her antiques and collectibles business on eBay. After years of amateur antiquing, Nancy received an appraiser's license, which puts her in touch with more potential inventory. She also speaks publicly at community groups about antiques and collectibles and often finds willing sellers among her audiences, either from offers of items for sale outright or by consignment. "The appraiser's certificate makes people more comfortable giving us antiques to sell," she says. "It's opened up new channels for us." The Baughmans wrote about their experiences in their self-published book Buy It, Sell It, Make Money.

Nancy also specializes in sterling silver, a skill she takes to some unlikely places to source her business: pawn shops. Although these businesses have a less savory status than antique fairs, Nancy has taken advantage of many pawn dealers' reluctance to do the research necessary to accurately price their inventory and put it on eBay themselves. "After all, their real business is making loans," she says. "They've got bigger fish to fry."