From the time your puppy was born it was handled by many people. Washing machines, dryers, television sets, radios, vacuum cleaners and telephones were a normal part of its day. Its breeder spent a tremendous amount of time with each puppy in the litter exposing them to all of life's little wonders. When you picked up your puppy, the breeder strongly recommended puppy kindergarten or obedience school.
You've heard many people say "I don't need to go to training class, my dog behaves beautifully in the yard." Well, what happens when that owner is walking the dog down the street and they encounter another dog? Or, when they are at the vets office and that well behaved dog suddenly becomes terrified when confronted with all those other dogs and cats? What's happening? The dog was not "socialized". In other words, it was not taught to behave around other animals in a variety of situations.
One way to help puppy with social skill is puppy directions, share, play nicely and learn the alphabet. Puppy kindergarten is basically the same. Puppies learn to listen to their owners, not growl when a toy is taken away, become accustomed to strangers and other puppies, strange objects such as umbrellas and folding chairs. They also learn a few basic commands such as come and stay in a loving, reassuring manner. In other words, they learn social skills.
These social skills create mentally "sound" dogs. Because they have been exposed to a variety of situations, slowly and lovingly, they are stable in just about any situation. Imagine a dog about a year old that has lived in a very quiet house and/or neighborhood. Everytime the garbage trucks come down the street the dog barks frantically and tears around the house. At the vet's office it tucks it's tail between it's legs and growls at other dogs. It shies away from the vet. One day construction starts on the empty lot next door. The tailgate of the dumptruck slams shut with a loud resounding "BANG!" The puppy takes off like a shot, hiding behind the sofa, shaking fiercely and wets on the floor. Because of it's reaction, the owner decides to take the dog to obedience school. Because this dog hasn't seen another dog since it was a baby puppy, all it want's to do charge the other dogs. Frustrated because of the dog's lack of attention and seeming inability to learn, the owner drops out of school ... then several months later, the dog ends up in the pound, unwanted and terrified.
If this dog has been properly socialized, in all likelihood none of the above would have happened. Study after study has shown that properly socialized puppies are easier to train. We all know that a well behaved dog is a lot easier to love. While you cannot prepare a dog for everything that will happen in it's life, you can teach it to not be fearful. If you start early and work hard with a lot of love and kindness you will end up with a dog that you can take anywhere.
Puppy kindergarten classes are usually held by clubs/trainers that also offer regular obedience classes. These classes are very structured with very specific rules such as: puppies must have proof of vaccination (prevents spread/outbreak of disease) and be a certain age/weight (so you don't have 9 month/90 pound puppies playing with a 3 month/30 pounder!)
To locate a class in your area, talk with your vet. He is a wonderful source of information. Ask if he knows of any dog clubs or dog training clubs in your area. Dogs clubs/training clubs can sometimes be difficult to locate as the members are volunteers and the organizations are non-profit. This means that their phone numbers normally aren't listed in the phone book. But, many will run ads in the paper (usually Sunday) announcing the start of obedience classes. Watch for Dog Show or Match announcements. These can also help you track down a "Kennel Club".
While you are sitting in your vet's waiting room, ask the owners of other puppies or dogs if they know of any good trainers. Check the newspapers under the animals for sale column or your local yellow pages. Classes, though sometimes are to find, are out there and lots of fun - track one down for your puppy's mental health - it's well worth it.