Training him not to bite is important too. Pay attention to his ears and his expression. Are his ears going down when he's going to bite? Try to say NO before he actually bites, or even if he snaps at you. Pick him up and put him in another spot. You break his habit of biting and he realizes it's not worth his while to bite.
NEVER give him a treat unless he's well mannered. Otherwise you are reinforcing his bad behavior. Reward him when he's being gentle and he will try to earn treats.

You need to let the cat know certain behaviors are unexceptable. This really works. It results in a gentle well behaved cat.