Jumping is a natural behavior for dogs. Dogs will typically jump when they want your attention or if they want something you have, like a toy or a treat. If your dog thinks you have something he must have, he may jump on you and bite to get what he wants. Dogs will also jump out of excitement when meeting somebody new. Having a dog who jumps and nips at you can be scary and also dangerous. Puppies typically bite because they use their mouths to taste and feel the world around them. They do not know how much biting hurts; it is just a natural reaction for them. If you have an adult dog who is jumping and biting, it is possibly because her behavior was not corrected as she aged, leaving her with a bad habit.
Teaching your dog not to jump and bite is imperative if you plan on taking your dog anywhere or if you plan on having company at your house. A dog who has bitten someone could potentially be in trouble with the law. So, you are going to want to have a dog who is well-trained, under your control, and not jumping and biting anyone around. For a puppy, teaching him not to jump and bite could potentially require several training sessions and reminders through repetition. However, for an older dog, you are changing habits they have built up over time. Either way, you are going to require some patience. Expect to spend several minutes a day, every time your dog is tempted to jump and bite, teaching her to forget this kind of behavior.
Along with patience, time, and commitment to your dog's obedience training, expect to have treats, toys to offer, and the idea of the habits you would like to see your dog have such as sitting when a guest comes to visit instead of jumping and nipping at your guests.