Since 1966, the International Book Project has collected over 150,000 books each year (in excellent condition); they use them for literary programs around the globe, donate them to Peace Corp volunteers, etc.
How does an organization qualify to receive books from the International Book Project?
The International Book Project accepts requests for books from organizations throughout the world, such as churches, missionary groups, primary and secondary schools, community and school libraries, universities, and the U.S. Peace Corps.
http://www.intlbookproject.org/inv-donbks.php