Soaring Books
Bryan Air Service - "10,000 feet and Climbing - The Aviation Adventures of Richard Schreder", by Karen Barbara - 
ASA - US Exam Preperation books and software
College Park Press - Very interesting Fundamentals of Sailplane Design book
Cumulus Soaring, Inc.
Kai Gertsen - Excellent Tutorials on Cross-County Soaring - Free Download
   - Introduction to Cross-Country Soaring
   - Off-Airport Landings 
GliderBooks.com - Comprehensive Flight Training Manual and Knowledge Handbook for Gliders
JP Aviation
Knauff & Grove Soaring Supplies
Oxford Web Publishing - Jim Hendrix's reviews of soaring books - very nice!
RD Aviation, Ltd.
Sailplanes.co.uk - Classified ads. and books and software
Soaring Books and Supplies - Bob Wander
Wings & Wheels