This is actually the title of an excellent book on the subject (available on this site), and if you are in this position then we strongly recommend the book to you.

However, there are certain basic guidelines you should follow:-
• Children should be taught that a puppy is not a toy, or a doll, and should never be disturbed or picked up when sleeping or eating.
• Children and toddlers often think it great fun to get the puppy to chase or play bite them. This is definately not a good idea!
• Children need to understand that there are some games that they should not play because they can actually encourage a dog's aggression. Some games will give your dog a chance to show it's strength and dominance by way of a contest - tug of war for instance - and it may look cute when puppies shake a toy or rope violently, but it is actually a throw back to their prey instincts when they kill their prey by shaking it to death. Not a good idea to encourage this with children around, although it is natural and will be difficult to eliminate.
• Do not allow the children to taunt the puppy as this may make it protective and jealous, and because your puppy will not always think things through, it may suddenly turn aggressive. Play fighting is included in this.
• Teach your children not to pull or grab a dog's tail. This can seem great fun as it always gets a fast reaction from the dog. Like us, your puppy cannot see what's behind it, and it is a natural reaction to quckly turn and even bite the offending hand.
• Owning a puppy or dog is a great way to teach a child how to behave responsibly. It is the responsibility of adults to supervise this, and to make the joy of owning a dog a safe experience. If you have children, or contact with children, and have got or are getting a puppy, then take time to read up on this, and you will all have a great time.

All information on this site is given in good faith, but should never be taken as final authorative advice. In all cases of doubt or query you are strongly advised to check the position with an expert - and your vet is the person to see first.