Puppy training can and should begin when the puppy comes to live with you regardless of the puppy's age. It is very important to be fair and consistant when training a puppy. If you take the time and effort to teach your puppy manners and set boundaries and limitations, you will eventually have the great dog that you have always wanted. It is much easier to train your puppy to avoid certain bad behaviors than to try to correct those behaviors in an adult dog. If everyone would take the time to properly train their puppies, there would be fewer problem dogs and not nearly as many dogs in animal shelters.