The following I am about to post on http://www.paperbackbookswap.com/ which is an amazing website for free books. Seriously. If you decide to join, if you would associate w/ my name: BaschaW, I'd appreciate it. Honestly, I was hooked because the first time I was looking for school books online I happened to find one of them ($100!! book) for free.
I've linked to the amazon page of the books for ease of researching if its a book you want or not.