Tips for Training Your Dog
According to Dr. Nicholas Dodman, a well-known behaviorist, dog training should be an enjoyable experience for both you and your dog. If you are not in the right mood for training, don't even start. Keep training sessions short, on the order of 5 to 10 minutes, to maintain your dog's motivation.
Dr. Dodman has some great tips in this article – please read 12 General Rules for Training Dogs.