Operation Paperback

Operation Paperback is a non-profit organization incorporated in the State of Pennsylvania that collects gently used books nationwide and sends them to American troops deployed overseas. Since 1999, they have shipped over 1.3 million books to locations around the globe.

How it works: http://www.operationpaperback.org/help_volunteer.php

First of all, you can make a monetary donation or be a volunteer shipper.

Quick Overview:
1. To be a shipper you begin by registering with them and accepting their volunteer agreement. There is no cost associated with this and your personal information is secure.
2. Once you have registered, you can log-in and request addresses of troops overseas using their automated system.
3. You input the genres you have on hand (mysteries, westerns, etc.) and the system will generate a customized list of names for your use.
4. Label your books and insert either their standard shipping letter or your own personal note.
5. Pack and address your box using the names they provide. Then head to the Post Office to mail your box. It's that simple!

Be sure to read the Frequently asked Questions to see what else is accepted: http://www.operationpaperback.org/faq.php