The websites mentioned below are great sources for dog training and dog related information in general:
The Association of Pet Dog Trainers (APDT) is a professional organization of individual trainers who are committed to becoming better trainers through education. The APDT offers individual pet dog trainers a respected and concerted voice in the dog world. We continue to promote professional trainers to the veterinary profession and to increase public awareness of dog friendly training techniques.
The Certification Council for Professional Dog Trainers (CCPDT) administers the national accreditation program for dog trainers.
Dogwise offers a wide variety of current cutting-edge dog books and products for serious dog enthusiasts and trainers.
American Kennel Club
American Sighthound Field Association