Organizations
1-26 Association
Air & Space Magazine
AOPA
Australian Soaring
Auxiliary-powered Sailplane Association - USA
British Disabled Flying Club
British Gliding Association
Collegiate Soaring Association
E.A.A. Experimental Aircraft Association
F.A.I. Fédération Aéronautique Internationale
F.A.I. Sporting Code - Rules for badge and record flights, See Section 3 for gliding rules
F.A.I. Approved Flight Recorders
F.A.A. - Federal Aviation Administration (U.S.A.)
F.A.A. - Federal Aviation Administration (U.S.A.) - Advisory Circulars
F.A.A. - Aeronautical Information Manual (AIM)
F.A.A. - Airmen database - database of pilots who have not asked to have their data withheld.  Includes ratings.
F.A.A. - Airworthiness Certification of Aircraft and Related Products - U.S.A,
F.A.A - Flight Standards Service - U.S.A.
F.A.A. - Flight Standards Service - Aviation Information
F.A.A. - FARs (Federal Aviation Regulations - U.S.A.
F.A.A. - Office of Air Traffic Airspace Management - Data files available on CD for $36 for U.S. airports, SUA's etc., Updated every 56 days
F.A.A. - National Flight Database - Data files every 28 days for $156/year
F.A.A. - Notices to Airmen (NOTAMs)
F.A.A. - Practical Test Standards
FFVV - Fédération Française de Vol à Voile
Freedom Wings International
General Aviation Awareness Council - U.K.
Gliding Federation of Australia
J.A.A. (Joint Aviation Authorities, Europe)
J.A.A. - JARs
J.A.A.- JAR 22 - Sailplane and Powered Sailplanes
Japan Soaring
N.A.A. - National Aeronautic Association - U.S.A.
National Air & Space Museum
National Soaring Foundation - U.S.A.
National Soaring Museum (USA)
National Transportation Safety Board (N.T.S.B.) - U.S.A.
New Zealand Soaring
Pacific Soaring Council, Inc.
Patagonia soaring ( 2450 km record site )
Sailplane Homebuilders Association - U.S.A.
Sailplane Racing Association
Soaring Association of Canada
Soaring Safety Foundation - U.S.A. - Very good data here!  Must read articles on safety from pilot and instructor standpoints. 
Soaring Society of America
Soaring Society of South Africa
Stratford-on-Avon Gliding Club: Disabled Pilots
Svæveflyver - Denmark
Vintage Sailplane Association
Women Soaring Pilots Association
World Class Soaring Association (W.C.S.A.)