Most people take home puppies around the age of 8 weeks and, given that, it's really never too early to start housetraining. One of the best ways to get started is to pick up your puppy if you notice him starting to go the bathroom and carry him outside where you want him to go. Be sure to reward him well, and he'll no doubt begin to learn simply by association. Just keep in mind that housetraining can take a great deal of patience and understanding.