Open Culture is a treasure trove of educational and cultural media. Avid readers and lifelong learners should definitely check out the site for its huge meta-lists of free textbooks, audio books and ebooks.
Photo by Chillihead
Textbook examples include: A Textbook of the History of Painting by John Charles Van Dyke, Rutgers; Project Management from Simple to Complex by Russell Darnall and John M. Preston, Eastern Michigan University; and Advanced Calculus by Sternberg Shlomo and Lynn Loomis, Harvard University. There are some high school-level textbooks included as well.
The 450 fiction, non-fiction and poetry audio books are available mostly as free MP3s but also some are in iTunes and other formats. Most of them are familiar classics, including works by Shakespeare, Jane Austin, Charles Dickens and Fyodor Dostoyevsky, but there are also more modern works from Neil Gaiman, John Updike and David Foster Wallace.
Finally, the collection of 375 ebooks come in iPad/iPhone and Kindle formats. Many can be read online too. The selection is similar to the audio books.