Reuse is environmentally preferable to recycling, following list offers examples:
Offer books to your local library, senior center, school libraries, friends, thrift stores, swap shops, and charities.
Big Hearted Books donate much of what they collect to nursing homes, prison reading programs, local libraries, as well as sell a portion of usable books, and recycle what can't be redistributed.
Textbooks can be a challenge to reuse because they get outdated. However, Green Textbooks, and Textbook Recycle both specialize in textbook reuse and/or recycling.