Check out these websites for more free materials:
Project Gutenberg: A curated collection of 34,000 downloadable ebooks in epub format. These classic titles are out-of-copyright. That means no waiting lists or restrictions!
Pixel of Ink: Features daily publishing of Free Kindle Books and Hot Deals.
The Online Books Page: Listing over 1 million free books on the web
Inkmesh: Ebook search engine to find free books and compare ebook prices for the Kindle, iPhone, Nook, Sony Reader, and more.
Just Free Books:Searches the content of more than 700 web sites, including gutenberg.org, wikibooks.org and archive.org. With JustFreeBooks you can find all sorts of free books: public domain texts, open books, free audio books, ad-supported books and more. Just type in the search box the book title, author or theme you want to find.
ManyBooks.net: more than 29,000 eBooks available for Kindle, Nook, iPad and most other eReaders, and they’re all free!