Where can you get a lot of Free ebooks and audio books for the kindle?

I want to get some ebooks and audio books for my dad so he can use for his kindle, what is a good website to get those formatsWhere can you get a lot of Free ebooks and audio books for the kindle?
The sites listed here have free ebook downloads:



http://www.howtodecide.com/ebook-downloa鈥?/a>



Also, if you master a good conversion tool such as Calibre,



http://calibre-ebook.com/



you'll gain access to more formats (such as EPUB) than just Kindle's native ebook file formats (AZW, MOBI).
A lot of the classic literature are available for free download from amazon for the kindle at the momentWhere can you get a lot of Free ebooks and audio books for the kindle?
PROJECT GUTENBERG



GOOGLE IT.Where can you get a lot of Free ebooks and audio books for the kindle?
amazon