Lulu.com is a marketplace for digital content on the Internet, created by people in more than 80 different countries. Lulu enables authors to publish their work themselves with complete editorial and copyright control and empowers them to sell directly to their customers and the rest of the Lulu.com global marketplace. With free web storefronts, social networking offerings and available global distribution, Lulu creators are fully supported to profit from their work.

Lulu has an elaborate website with a plethora of information. You can read their full FAQ here.