Throw the first ball and let your dog go after it. When your dog starts to come towards you, ask your dog to "drop it."
If your dog does not drop the ball, stop paying any attention to your dog and take out the second ball.
Start to have fun with the second ball. Toss it up in the air. Act like you're having a great time with the second ball. Keep doing this until your dog looks at you. If you've done this step correctly, your dog will drop the ball that he/she has and look up at the one you have.
As soon as your dog drops his/her ball, show the ball you're holding to your dog. As soon as your dog focuses on the ball that you're holding, throw it.
Repeat the process when your dog comes back to you. Within a short period of time, you'll have your dog retrieving for you.
How to Teach Your Dog to Fetch Provided by eHow.com
ERIC LETENDRE, eHOW DOG TRAINING EXPERT
Eric Letendre, author of the book "The Amazing Dog Training Man," has been professionally training dogs for the past 18 years and has helped literally thousands of dog owners learn gentle and effective training methods to teach obedience and solve behavior problems. On Eric's website, www.AmazingDogTrainingMan.com, he offers over 1000 pages of dog training tips, videos, and articles as well as dog training books, DVDs, and online dog training courses.