It is a puppy phase, I guess. Huey drew blood on me and dh by snagging our nasal septums with his teeth. I learned that when he bit, to yelp loudly like another dog would and act hurt (even if I wasn't), and he fairly quickly learned what behaviors caused us pain. That seemed to work better than disciplining him. We did have a few bloodlettings in the meantime...
We got him very young at 7 1/2 weeks-we didn't know better at the time- so he didn't learn bite inhibition from his mom before coming to us.