Best for: Collectibles and distinctive items — Pez dispensers, your grandmother's Hummels, a vintage camera.

How they work: You put your items up for auction and then wait for buyers to bid against one another. After the auction is over — a typical one lasts a week — you and the highest bidder arrange for delivery. And don't worry about getting stuck with a low bid. You can set a reserve price that is your line in the sand. If no one bids at least that amount, you have the right to pull the item off the market.

Where to go: In the auction world, www.ebay.com is hard to beat. It currently has more than 12 million listings in play, compared with 250,000 on its closest competitor, Yahoo! Auctions (auctions.yahoo.com). Unless you're a die-hard iconoclast or a fan of the underdog, there's no compelling reason to look beyond eBay. The site has plenty of useful hand-holding tutorials to get you started. It usually doesn't take an absolute beginner more than an hour to get her first item posted. You can also get more help and tips from eBay for Dummies ($22, www.amazon.com).

Pros: A huge pool of prospective buyers, many of whom are trolling for arcane goods. A streamlined system that makes setup and monitoring simple. Customer reviews for each seller are another great feature: Once you develop a good reputation as a seller, your on-line rating will be an enticement for more folks to do business with you.

Cons: For bulky items, a national auction might not be the smartest move. Either you're stuck with a hefty shipping bill or, if you require the buyer to pick up the bill, you won't attract too much attention. Then there's the cost. Listing fees range from 30 cents to $3.30 per item, based on your asking price. When your item sells, eBay collects an additional fee from you — 1.5 to 5.25 percent of the final price. There is also a risk your buyer will back out of the deal. Then you will have to start all over again.