Socializing your puppy
All puppies need to meet as many other dogs and as many people as possible. This is the essence of socialization and, when done effectively, most of the behaviour problems that may occur can be avoided.
From the day you get your puppy he should start meeting new people. Don't overwhelm him but within reason, the more people he meets the better. These people should also hold the puppy, and be asked to play with him, so that he learns that people are friends.
Until the puppy has all of its vaccines some caution is necessary when it comes to meeting other dogs at this point. Wait until your puppy has its second round of vaccinations which generally occurs at about 12 weeks of age before meeting other dogs and puppies. If there are other dogs in the household they should be introduced as soon as possible.
Once your puppy has all of his vaccines hire a dog walker who has other puppies so he can be socialized with others starting out when he's young. Don't wait until he is too old as it's important for him to learn develop dog social skills. This is something a human can never teach a dog. Many dogs who did not learn to social skills at a young age can become fearful of dogs and aggressive at a later age. You can also enroll him in a good dog day care. Being around other puppies in a dog day care centre will be all the socialization he needs to grow up to be a friendly well-adjusted dog.