Hello. I am cleaning out the garage and am donating a bunch of books to charity. I have a receipt from the salvation army for a couple hundred books but I don't know how much they're worth. Is there a general rule of thumb for how much books are worth when they are donated to charity. They are mostly soft back fiction books. I don't want to go through the trouble of finding the worth of each book individually because I have a ton of books so I'm just looking for a general rule of thumb for deducting the books.