Wanted: Paperback books at the end of their life

I'm looking to make a paper project out of the pages of books, but I'd like to use books that are falling apart/at the end of their days rather than perfectly good books that I'd feel guilty cutting up. I'm looking for paperback books with normal to thick paper, anything thinner won't work for my purposes (average book paper is perfect, but I know some novels use thinner paper and that wouldn't be stiff enough). Ideally these would be free to me, as I guess these books would otherwise be recycled/thrown away. These books need to be all print (no pictures) and not moulded or water damaged.