Previous to bringing your new puppy home for the first time, he will have been playing a lot with his litter-mates. It is natural for puppies to play-bite their brothers and sisters, when he has become comfortable with his new home and his new family, he will try to play with you the way he played with his litter-mates, by biting! This is an unacceptable habit to promote, you must teach him to play with toys instead of your hands.
To train your puppy to play-bite toys instead of you, get a large soft toy and keep it at the ready for when you choose to spend some time with him throughout the week. When your puppy gets excited he may try and bite your hands or your fingers. Keep your hand steady so you don’t make him more excited and make a fist so it becomes harder for your puppy to chew, try and distract him by offering a toy in place of your hands. It is easy for puppies to lose focus, keep the toy moving, wiggling it or moving it around the floor (puppies may get confused if you throw the toy, so it is best not to do this manoeuvre until he becomes more familiar with this game) so that the game remains interesting.
Enforcing rules and limitations on your puppy can be difficult, especially in the beginning when his behaviour is considered cute and innocent, but these rules are necessary for making sure he grows into a well behaved adult. During playtime with toys, impose the rule that any behaviour you deem unacceptable will immediately put an end to the game. The kind of behaviour that falls under ‘unacceptable’ includes any action that you do not what him doing as an adult, like barking for toys, growling at children, jumping on visitors etc. Your dog biting a child while playing a game of tug-of-war or slamming into a child as he tried to get the toy out of their hand is not only considered unacceptable, but dangerous.
The habits that you teach now will become your puppy’s normal behaviour when he is older. As soon as he exhibits unwanted behaviour, stop any interaction with him and remove all toys. It won’t take long for your puppy to learn what causes the game to end, when he does, he will stop behaving in such a manner so that playtime can continue.