Just a quick note to let you know about an excellent ebook site that I found recently - The Ulitmate E-Book Library (TUEBL).
TUEBL is a website run purely to give access to free ebooks for those that can't (or won't) pay. Nice! Just like your local library - nobody is 'paying' to read the books from there are they?
Anyhow, I take my hat off to the people that run this site. Top work. You can even 'like' them on Facebook to keep updated and there's a monthly email newsletter as well.
There are always new books being added in epub format but you can use a converter like Calibre to convert them to another format if required.