I have a 6 month old rottie named Spook. He has a hard time learning not to jump up when he see's someone new, or bites them.. Since he's going to be a big dog, I want him to stop biting before he could actually hurt someone.. And I no that he might grow out of it.. But I need some help on him. Any ideas on what I should do?:confused:

When ever he bites. Say STOP IT!!
The louder the more effective

He needs to learn to stop this behavior pronto! With really young puppies, I deal with biting too hard by "yelping"--loud and shrill, as if the puppy has mortally wounded me--get up and turn my back to the little demon. This usually produces a startle reaction, which is exactly what you want. Wait a few seconds, then go back to the puppy with a toy and try to decrease the excitement level in the play. If he persists, do the yelp again and walk away. This is similar to what the other pups in the litter do if one gets too rough. He may still be young enough for this to work. Don't ever use your hands as toys or allow anyone else to play with him like that; hands are there to feed and pet, never to be feared or taken for granted as chew toys.
The jumping up is a throwback to wild behavior--wolf pups greet their mother by licking at her mouth, and this stimulates her to regurgitate food for them. Gross, but she doesn't have pockets, so she carries the goodies in her stomach.
Some people will tell you to knee the dog in the chest, but not everybody is coordinated enough to do this (including myself), and this is going to be a BIG dog.
Teach him the "sit" command. When he runs toward you, turn away from him and tell him to sit. When he does, bend down and greet him on his level. If he doesn't sit, ignore him as best you can. I find that stepping "into" the dog's space and bumping off with my hip, while still keeeping my body turned away helps. He is never to be greeted, petted or acknowledged if he jumps up. This is not going to stop overnight. He has to learn that this same rule applies in every place, with every person. Dogs don't generalize very well, so it may take a while before it sinks in.
My mantra is "Behavior that gets rewarded gets repeated". He only gets rewarded when he is acting civilized.

Thanks.. this helps a lot.. But the command "Stop biting" or "no bite" only seem to make him more roudy. And yelling at him has no effect. If I turn away from him, he bites my bum. And he has a strong grip too, so it takes a while to remouve his mouth from my jeans. Help?

Sorry, I have been away & didn't see your post sooner. So this dog is the sneaky sort.. A lot of dogs seem to think that us yelling at them is like barking back--making the game rowdier, just like you said.
Normally, I keep walking right into a bouncy dog's space until he sees that I am going to claim right-of-way. Not sure this is the thing to do with one so big and mouthy.
Are there any dog trainers near you? Maybe your vet could recommend someone. If you are totally without help, it sounds like it is time to look into a Gentle Leader Headcollar.
If you are not familiar with these, they fit more like a horse halter than a collar and they really do make handling a big headstrong dog easier.
Take a look at them at Premier.com. They really should be fitted by someone familiar with them, but if you decide to try one, I can try to talk you through fitting it. THey have a really good instructional video available also. Make sure it is a Gentle Leader, and not a Halti or something else. I have had overall very good results with these. They are humane, you have much more control over the dog, and they allow you to close the dog's mouth. Let me know what you think.

Try to replace the people biting with toys. Like rope toys (get the rope from home depot, or somewhere and make your own for a dog that large) to try and fulfill his biting needs, or try spray bottles, just make sure he doesn't see it.