Well the fact that you reposted tell me it may be a serious question. I am no expert just have my own experience which is also limited. First off all search the forums for "biting" there is a TON of thread devoted to it. Second educate yourself, the GSD did not get the nickname "furgator" for nothing. THEY BITE while they teeth, all you can do is correct it and wait it out which takes about 4 months and longer! Some tricks that are used are replacing your hand (if thats whats being biten) with toys, also yelling loudly OUCH so the puppy realizes he is hurting you. I WOULD NOT EVER suggest "aggresive action" towards the pup because that will in turn cause him to react. kind of you hurt me ill hurt you back thing and then your in for a very long and sad road. Your puppy's mouth hurts and is going to for a while, try giving him a small ice cube, or PLENTY of chewy toys, other than that I would HIGHLY suggest searching the forum!!
"German Shepherd, Anything else is just a dog"