I belong to an online book swap, PaperBackSwap, which is where I get and give most of my books. Each time you ship a book to someone who wants one of yours, you get a credit to "buy" a book from someone else on the site. It's a great way to recycle books.
This year they are running a donation drive, Books for Schools 2012, wherein you can donate money or unused book credits to the site. For each credit donated, a brand new book is purchased for a school in need. This year's schools include those affected by Hurricane Sandy as well as Sandy Hook Elementary School in Newtown, CT. Living in New Jersey, these are two causes near and dear to my heart.
I donated my book credits this morning to Sandy Hook Elementary. I'm glad to help in any small way I can.