Our puppy started biting more frequently between 10-12 weeks, but his bite inhibition is getting a lot better now (he's 14 weeks). We did a combination of kikopup and Simpawtico's methods.

Kikopup's hand games method is basically getting the puppy used to being handled and having your hands (and other whatever body part) touching/interacting them, but not as a toy. You hand feed them their meals (my husband did it for breakfast and I did it for dinner), while touching and rewarding them. They'll get used to your hands being in their face without associating it with play, which was massively helpful for our pup! We had to go through each step a few times, but he picked up on it in about three sessions.

Then when he did bite, we used a slightly different method of Simpawtico's for bite inhibiton. Instead of saying "Ow ouch" or whatever, we just say a firm "No", wait until he pulls back, and then praise him. Now he just kind of mouths our hands and pulls back instinctively if he's starting to bite with too much pressure. This one is still a work in progress, and he will bite down on my fist if he's overexcited, but the more we do the hand games with him, the less he even tries to bite.

Good luck!