http://gen.lib.rus.ec (Use a proxy if you are having issues connecting)

http://textbooknova.com

http://en.bookfi.org/

http://www.gutenberg.org

http://ebookee.org

http://www.manybooks.net

http://www.giuciao.com

http://www.feedurbrain.com

http://oll.libertyfund.org/index.php?option=com_content&task=view&id=380

http://www.alleng.ru/ russian site

http://www.eknigu.com/ russian site

http://ishare.iask.sina.com.cn/

http://2020ok.com/

http://www.freebookspot.es/Default.aspx

http://www.freeetextbooks.com/ need to signup

http://onebigtorrent.org/

http://www.downeu.me/ebook/

http://forums.mvgroup.org (need to register)

http://theaudiobookbay.com/ (audiobooks)