Training your puppy should not start after he gets his first set of shots nor any time after that. Training should start the first day you take him home. Getting him used to a crate and used to his routine will make a big difference in how he behaves as a teenage and an adult. Since there's so much I could say about puppy training, though, I'll focus on the stage approximately between 8 weeks and 16 weeks old.
If you own a puppy, perhaps the above picture looks familiar. You try to pet your puppy and he tries to bite the crap out of you. He bites your ankles, your feet, your hands... and really anything he can get his mouth on. If you tell him "No," sometimes he might stare at you with a devilish look and lunge at you, even at your face. Is this something to worry about? Do you have an aggressive dog on your hands? Chances are that you don't. What you have is a puppy testing his limits, treating you like another puppy and "trying" out his dominancy skills.
I've had almost all breeds act this way, although the pressure of their bite can vary. You might be tempted to run away, put the dog in his crate or put the dog outside. But you are just avoiding a situation that could really be used as a learning tool for your new little beast. So be prepared for a few puppy bites (yes, those razor sharp teeth HURT!) but if you practice with your puppy, teaching him what behavior you like versus the behavior you don't like, it will click... eventually... I promise.
If you are a parent, you might remember those days when you didn't have a lot of control over your toddler. Maybe your child would reach for something she shouldn't have or something dangerous, and you would redirect her to an acceptable item. (No, no, don't put that pen in your mouth... here's your toy!) It's the same thing for your puppy. If you sit on the floor with your puppy and a couple of toys (not hundreds... let's make the puppy excited about the toys, not bored because there are too many), try giving the toy to your puppy. If he's chewing on the toy, tell him with a positive tone, "Good dog" or "Yes." If he mistakes your fingers for a toy or chomps down on you instead, make a startling noise ("Eh! Eh!"). In most cases, the puppy will release. Then replace your hand with the acceptable toy.
Here I am with a chocolate Lab puppy, Dakota, teaching him that it's okay to bite the toy, but not okay to bite me.
The one thing to keep in mind is that before 4-5 months old, a puppy doesn't care that much about verbal praise or even that much about petting as a reward. A tired puppy might like to snuggle or be pet, but if your puppy is full of energy, chances are that he prefers to bite than to be pet. Pick your battles. Don't force him to accept cuddles if he's feeling rambunctious. Likewise, if you don't have time to work with him when his energy level is high, give him something to occupy his attention (kong with frozen peanut butter in it, a bone filled with treats, an interactive toy). Sometimes you may need to put him away in his crate or behind a baby gate. Work with your puppy if you are able, but it's okay if you sometimes don't have the time. Just be prepared to choose another time to play with your puppy and teach him what is acceptable to chew on. There were definitely days when I told my kids not to interact with Piper because she was in "Hyper Piper" mode. Instead of making my kids afraid of their puppy, I told them to come back and play with her once she'd settled down.
There is so much more I could say about puppy training, but you'll just have to hire me to find out. :-) Meanwhile, if you have a young puppy that is biting you, acting more like a shark than a puppy, don't worry too much. It is definitely a stage young puppies need to go through... and there is a light at the end of the tunnel.
