United States Equestrian Federation, the national governing body for the Olympic and World Championship equestrian sports.
The Federation Equestre Internationale (FEI). The international governing body for equestrian sport
Pacific Coast Horse Shows Association (PCHA).
Orange County Horse Show Association
Greater San Diego Horse Show Association

On-Line Publications/Magazines
California Horsetrader Magazine
Chronical of the Horse
Magazine of hunter/jumper, polo and dressage competition in the United States.

Other Great Resources

Tack and Feed store located in San Juan Capistrano

All your horses supplemental needs, and tack and clothing too!

Horse Show Links
Horse Show Time - Events/Results
Hits Horse Shows In The Sun

Blenheim Showpark Equisports