Good advice a lot of folks need to hear, Roz.
Years ago, the UCF library would take old, out-of-date books, ship them off to be recycled, and make a little money from them. One of their senior librarians is a good friend of mine, and she was happy to take them, until they stopped doing that.
People who really can't bear to trash those old books (like the Word 2013 user manual that's still on my shelf) should try to find an agency/organization that has a recycling program. Or have a garage sale (and you'll see how much those old books are really worth).