If you've just bought or adopted a puppy, know that one day, the "Biting Phase" will start. They're gonna grow sharp little teeth that make you yelp when they chomp down. Don't worry! They never bite hard, and are just testing their teeth.
However, it is very important to know how to react when puppies bite you. Always yelp or cry out if pains and put your puppy down for a few minutes. It's important that the little fellow realizes that it's not really acceptable to bite family members hard, and not acceptable to bite non family members at all.
Never whack your puppy if they bite you since I really feel they won't understand why you're doing that. If you find that your dog is biting or damaging the furniture, you can get certain non toxic substances from your local pet store that creates a bitter taste that makes furniture unattractive to the puppy.
Puppies will grow out of the biting phase in time. When their teeth are growing, it relieves them to chomp down on something. Till then, try and even enjoy this phase! When your dog is old, you'll remember the time he used to tug on your jeans with this his wagging.