In addition, check out Sophia Yin's website[1]. It's chock-full of free videos and articles. She also wrote an excellent book[2], which I highly recommend to all dog owners. I train dogs as a hobby (agility with my own dog, plus I do volunteer work for puppy and obedience classes). As a warning, dog training is highly addictive for both you and the dog!

[1]: http://drsophiayin.com [2]: http://drsophiayin.com/howtobehave