Affordable Learning Solutions: Open Educational Resources by College

Flat World offers a variety of English textbooks online for $19.99. Print versions are also available.

HathiTrust is a partnership of academic and research institutions, offering a collection of millions of titles digitized from libraries around the world.

Project Gutenberg offers over 40,000 free ebooks, which can be read online or downloaded. These books are all in the public domain.

MIT Open Courseware offers an extensive series of online courses in literature and writing. Courses generally include lecture videos, assignments, exams, and more.