Understand Why Your Puppy is Jumping
Most puppies will go through a jumping phase at one point or another in their early life. It's good to have a head start on how to handle and properly manage this behavior and it's equally important to understand why it's occurring in the first place. Puppies jump because they are trying to get your attention. It's that simple, they're down on the floor and to get closer to you they jump. It's important to understand this because it helps us resolve the underlying issue. If your puppy is jumping to get attention and they get attention by getting eye contact or being pet, then this behavior is being reinforced and will likely be repeated. The BEST way to handle a jumping puppy is to ignore this behavior completely and turn your back to them. Doing this teaches them that jumping actually gets them less attention and over time they will learn to stop the behavior.
Many people make the mistake of pushing the puppy down or telling them "off" but truly, even though these are well meant actions, they still give your puppy attention. Bad attention is still attention and therefore reinforces the behavior. Giving them that eye contact, touching them, and speaking to them is exactly what they're seeking. Many people inadvertently encourage the behavior without even knowing it.
Properly Manage the Behavior
Next on your to do list is going to be properly managing the behavior so that you can set your dog up for success. Using baby gates or puppy pens are wonderful management tools to use when you are training your puppy in the beginning. It's not a great idea to begin your jumping training when your puppy is already bouncing around and clearly going to fail their lesson. Instead you can use these tools to help aid your puppy by giving them some time apart from the person before their interaction. This gives your puppy time to calm down and will give you a better position to engage with them from.
Once your puppy has learned how to properly greet you and guests, then you may phase out the training tools. However, in the early stages of training these can be extremely helpful in preventing your pup from developing bad greeting habits. Remember that what's reinforced is likely to be repeated so you want to prevent as much reinforcement for this behavior as possible. Using these tools will help give you the confidence to slowly build your dog's greeting manners.
Teach a Replacement Behavior
Lastly, teaching a replacement behavior is going to be your fastest way to success when teaching proper door manners. Teaching a replacement behavior simply means teaching your puppy to do another behavior as an alternate to the behavior you'd like to get rid of, in this case jumping. Teaching your puppy that you'd like them to sit to greet you and others is a perfect replacement behavior to train. This gives your puppy a task to do and also gives you a way to encourage a wanted behavior instead.
This is something that can be taught as soon as you see the jumping behavior arise. In any situation where you think they may jump, ask them to sit instead and then frequently reward them for sitting. It's great to keep treats by the entrance for this practice so you can get in many repetitions. When this training is repeated several times over several weeks you'll begin to notice your dog will automatically start sitting to greet you. Always be sure to reward them as soon as they sit with food rewards in the beginning gradually transitioning to verbal phrase once the behavior is solid.