Textbooks

Academic Book Services, Inc.
Grades K-12 reconditioned used textbooks, reference materials, workbooks and paperback titles.
http://www.academicbookservices.com

Bare Bookz
Buys and sells used textbooks; registration required to enter.
http://www.barebookz.com/home.htm

The Book Cellar
Specializing in college-level technical books and Christian homeschooling curriculum.
http://bookcellaronline.com/

Book Swap
College textbooks exchange; student to student sales.
http://www.bookswap.com/bookswap/

Bookbyte
Sells college and school textbooks.
http://www.bookbyte.com/

Bookcircus.com
Used and new textbooks, study aids, dictionaries, encyclopedias, thesauruses, reference materials, classic literature, and bestselling novels for K-12 and college.
http://www.bookcircus.com/

The Cat's Pajamas
Offers new and used homeschool materials. Searchable by grade or language.
http://www.thecatspajamas.org

Class Book
Used, and some new college textbooks. Buyback service based at East Greenbush, New York.
http://www.classbook.com

Follett Educational Services
Used textbooks for grades K-12.
http://www.fes.follett.com/

Free Book Express
Textbooks and novels, with a 12 site price comparison feature.
http://www.freebookexpress.com/

Local Texts
Free listings for college textbooks. Search by schools.
http://www.localtexts.com

PDX Books
Buy and sell college textbooks as well as compare prices at online bookstores.
http://pdxbooks.com/

Powell's Books
Carries an extensive collection of rare out of print used textbooks, reference materials, and technical titles.
http://www.powells.com/booksforstudents.html

StuBex
Book exchange for US and Canadian college students. Registration required.
http://www.stubex.com/

Texas Book Company
Sells new and used college textbooks. Includes online search.
http://www.collegebooksdirect.com/

Textbook Exchange Canada
Buy and sell used textbooks in Canada.
http://textbookexchange.ca

Textbooks For Sale
A selection of used college textbooks.
http://www.geocities.com/tbooksonsale/