- Textbook Revolution - This student-run site is one of the most popular places to find free textbooks on the Internet. Textbooks are available in PDF format and e-textbooks are available that can be viewed online.
- Flat World Knowledge - This site provides free, peer-reviewed textbooks written by expert authors. All of the site's materials can be viewed for free online, printed for a small price or purchased as an audio file.
- Connexions - Connexions offers a variety of open educational content, including free textbooks. All of the free textbooks are available to read online, and some include accompanying homework guides and other helpful materials.
- Textbook Media - Fremium Textbooks, real books written by experts and assigned by instructors, are available at this site. These textbooks include ads, but are free, digital and available to anyone - all you need to do is sign up for a free account. Textbook Media also offers ad-free versions of the no-cost textbooks for a small fee.
- FreeTechBooks - Find links to hundreds of free textbooks and tech-related books online. Most of the books on this site can be viewed and printed free of charge.
- eCampus.com - This site provides every textbook buying option imaginable. You can choose from new or used books, e-textbooks and textbook rentals. eCampus.com also offers a textbook buyback program.
- CampusBooks.com - This site compares prices on more than 8 million textbooks around the web so that you are guaranteed to find the best price online. Site shoppers can choose from new or used textbooks, e-textbooks and rentals.
- Chegg - Number one in textbook rentals, Chegg offers thousands of textbooks, free return shipping and customizable renting periods. This company will also plant a tree for every textbook you rent, sell or buy through the site.
- CengageBrain.com - At CengageBrain.com, you can save up to 15% on new textbooks and 50% on e-textbooks. The site also sells textbooks by the chapter and in audio form.