American Kennel Club – Photos and complete descriptions of the 150 recognized dog breeds, current registration statistics, as well as upcoming events and several publications.
American Rare Breed Association – Information on rare and exotic dog breeds, those not currently recognized by the American Kennel Club.
Certified Dog Trainers - Certification Council for Professional Dog Trainers
Dog Fancy Magazine – Breed profiles, articles, and more for the dog enthusiast.
DogLuvers.com – Browseable and searchable for hundreds of dog breeds with additional information on medical conditions, training, development, etc.
Dogs – Articles on all aspects of dog ownership, and a forum where you can meet other dog enthusiasts. From About.com
Dogs 'n' Kids – A slide show about responsible dog ownership.
Dog Owner's Guide – Articles on all aspects of canine disease and health.
Woof! It's a Dog's Life – From the PBS series "WOOF! It's a Dog's Life" with Matthew Margolis -- answers to your questions using simple and effective dog training techniques and his trademark philosophy of "love, praise, and affection."