2. Selling books, music and other products

Amazon. com and eBay revolutionized e-commerce in the 1990s. Since then, countless individuals have made money selling books, movies, clothes and every other commodity under the sun.

E-commerce is becoming easier than ever, and the complications of arranging payment over the Internet are disappearing fast, Spector says.

"A lot of the uncertainty is taken out of the equation thanks to the technology," he says. "You're going to get paid before you send out the product."

Spector, author of the book on Amazon. com. says sites like Amazon can help small-volume sellers reach a wider audience.