SearchinQ

http://www.bridgedoctor.com
Interactive Contract Bridge lessons. Live games. Competition ladder. Friendly online Bridge Club. Ideal for beginners and intermediate players.

http://www.bridgeworld.com/
Features an overview to bridge, practice problems and puzzles, bookshelf catalog of over 250 titles, and an introduction to the Bridge World Magazine.

http://www.kantarbridge.com/
Books, tips, articles and lessons for the Card Game Bridge by professional bridge player and author Eddie Kantar.

http://www.ebu.co.uk/
Organizes bridge in England. Provides schedule and results of national tournaments, bridge teaching programme, and membership information.

http://www.fifthchair.org/
Not-for-profit organization devoted to fostering online bridge education.