What books on puppy training have you read?
Seems like everybody has a different take on what to do about nippy
pups.
The Monks of New Skete's 'The Art of Raising a Puppy',
Brian Kilcommons 'Good Owners, Great Dogs'
and James DeBitetto's 'You And Your Puppy' are three of my training
books.
You could also have a trainer come out to your house (very important)
and work with you, the pup *and* the kids.
Puppies gotta run and be nuts sometime. They gotta bite and chew on
something. The trick is letting 'em rip something, somewhere ( other
than the kids and in the house) and teaching them that there's a time
and place for everything.