sounds like a case for Cesar Milan the Dog Whisperer.
Plenty of exercise is a just......on a leash not just bouncing around the house.
One thing I've read in various books is you should have the dog sit or preform some "trick" before you give him his meal. Also stand near the dog when he eats. Pick up his bowl while he is eating and then give it back. This lets the dog know you are in charge.
of course if he is beyond allowing that to happen you may have to try a trainer.
It is important to not allow a dog to bite or mouth your hands for any reason.
Of course....this is one of those situation where I have to say....'do as I say...not as I do'. Because my 18 week puppy still bites at my handsmany time per day. Especially when I put on his leash or brush him. As if he is playing...but that playing is not "cute" and will have to be corrected. I'm getting there ,...but he still does it often.
Good luck