A puppy can and should begin to learn social skills long before you complete his vaccination schedule. Socializing a young puppy is critical to his chances of having a happy and healthy life. If you wait until after the vaccinations are fully done, you miss that all-important period between three and 12 weeks, during which puppies are most curious and accepting of unfamiliar people, places and things. Puppies begin to get wary of new ideas as they age.
Early socialization almost guarantees your puppy will have a better chance at a longer and happier life because he will have learned skills that will make him a better companion animal. This makes it less likely that he will end up in a shelter or banished to the outdoors because he's not reliably safe around new people. The risk of contracting a disease because he is not fully vaccinated is mitigated by the importance of early socialization, but it needs to be done safely and under direct supervision.
Puppies with siblings have an advantage over single puppies because they must learn early on how to get along well with others. Puppies should be handled frequently and gently in their first few weeks of life. Exposure to a variety of types of people will help your puppy become comfortable with a diversity of ages, genders and races. The more exposure to new people, the more comfortable he becomes. Taking him to assorted places where he is not likely to meet other puppies is also a good way to get him accustomed to new concepts. Take him with you when you visit friends and relatives.
Puppies get their first set of vaccines at 6 to 8 weeks of age. The normal set of vaccines include distemper, measles and parainfluenza. Bordatella is optional but it's wise to opt for it so you can to take your puppy around other dogs with more confidence that he'll be protected against kennel cough. At the age of 7 to 8 weeks, about a week after the first set of vaccines, enroll your puppy in a carefully supervised puppy kindergarten class. The class facilitators should insist on seeing your puppy's vaccination record to date and proof that the dog does not have any external or internal parasites. These precautions ensure the safest environment possible. Any accidents should be cleaned up immediately with a disinfectant. Vaccines and deworming protocols should be given a week prior to beginning class.
Some places to avoid until your puppy has been fully vaccinated include dog parks and doggy day care facilities that do not separate very young puppies from older dogs. Walking your puppy on neighborhood streets where other dogs frequent is a good way to socialize him to other dogs, but not until after he has had his full set of vaccines. Until he is fully vaccinated, it's best to allow him to relieve himself in or near your own yard where the risk of contamination from other dogs is lowest.