Dogs that jump up on people are a nuisance at best and dangerous at worst. This problem is easy to correct and even easier to deal with while the dog is still young (and presumably smaller). Dogs that jump are generally doing it for one of two reasons: to greet you or to express dominance. Dogs that are excited to see you jump up to get closer to your face, so they can smell your breath, which is one way they use to identify you. Dogs that jump and remain still with their paws on you are vying for social dominance. If you push the dog away, these dogs become more frustrated, so they jump with even more determination.
You can use a number of methods to stop problem jumpers. One is to teach the dog to sit. Every time the dog approaches you, tell him to sit before he can jump up. Be sure to praise him enthusiastically when he does sit. If this doesn’t work, you can enlist the help of a friend. Put a training collar on the dog and hold the end of the leash. Have your friend encourage the dog to jump by patting her chest and making happy, excited noises. If the dog jumps, pull him down and say "no" emphatically. Once he’s on the floor, praise him. After a few repetitions, most dogs won’t fall for the ploy anymore and will just sit down when you encourage them to jump.
Another approach you can use is based on the fact that dogs have an inborn reflex to withdraw their paws if you hold them. When the dog jumps, grab his front paws and hold them firmly until he tries to pull them away. As soon as you feel the dog move his paws, release them and praise him when all four feet are back on the floor. Alternatively, when the dog jumps, you can grab the front paws and walk the dog three steps backwards to throw him off balance. Most dogs are disturbed by this technique so that jumping quickly seems like a bad idea.
Many dogs that jump are brought to shelters because their owners "couldn’t deal with it." This flaw doesn’t have to be fatal, however. Depending on the size and temperament of the dog, one of these solutions coupled with a little patience can work wonders.