Where to get books for very cheap?

Amazon.coms used book section. (Look under the title on the page for each book and it tells if they have any used. In there is Goodwill and many other cheap, but reliable, used book places, but don't forget to check the ranking. Anything above 97% with lots of votes is a good place, since someone will always hate a place.)

you can get most books in Public Domain as ebooks from Project Gutenberg

http://www.gutenberg.org/

there are book exchanges like Book Mooch

http://bookmooch.com/ I have seen the ad but have not tried it.

free audio books from Podiobooks

http://podiobooks.com/

mostly for dead tree books I would agree with Daisy but in my town also ad the Friends of the Library used books sale

i'm a bibliophile and very frugal. I usually get them at goodwill, salvation army or garage sales. Second hand book stores are also good. they usually give you credit for books you bring in.

you torrent them