The online auction sites, headed by the financial monster, eBay, are a wonderful source of quick income if you are willing to put in the time to learn the ropes and are also willing to begin by failing. Stories about simple folk selling toast carved into religious icons and making a mint are legion. The reality is that you are probably going to fail the first few times you attempt an auction. It takes some experience to write advertising copy, which is what the auctions listings are. The old saying, though, that one man's trash is another man's treasure, holds true nowhere as much as on the auction sites. Follow these rules, and you have a good shot at either making some quick cash or finding a long-running source of income on the auction sites:
Spend some time watching auctions on whichever site you've chosen. Learn what sells and when, and at what price. Choose one or two items of the type you are thinking of offering, and keep track of their progress. If the seller relists the item because it hasn't sold, check the relisting for changes. Make note of what works and what doesn't.
If you are capable of producing something that other people want to buy, start small with one or two auctions. If your product sells, then you can increase the number of listings.
Don't give up too quickly. Like all retail markets, the online auctions have a cyclic nature. Think about where you would sell your items if you had a brick-and-mortar store, and during which season you would expect the majority of your sales.
Keep careful records of what you have sold and at what price. eBay sometimes makes mistakes.
Use the online cash transfer options. Paypal is owned by eBay, which is owned by Yahoo!, so it's a closed-circuit and reasonably safe. There will always be glitches, but you're less likely to be stiffed by a buyer if you have the cash transferred directly to an online paypal account than if you accept a personal check or money order.
Have a back-up plan. If this doesn't work out, what will you do next?