Training a dog not to jump is counterintuitive to what we as humans think it should be. However, it's easy to train if you can convince everyone in your family to respond consistently each time your dog jumps.
Train a Reliable Sit
Though you aren't going to be able to train your dog to sit for the first time when you first walk in the door after an 8-hour day, you can teach it as a default behavior so that your dog soon reverts to it when he isn't sure what else to do. Since most dog default behaviors are undesirable to us (jumping, barking, digging), we need to train new ones.
Sit is a good choice when training a dog, because it's easy to learn. To teach, hold a treat directly above your dog's nose and move it slowly toward your dog's rear. As he looks up to follow the treat, he will sit. As he's sitting, say the command. Just say it once. Don't repeat it over and over.
Repeat this three or four times before taking the treat out of your hand and just using the hand signal. Once your dog sits, reward with a treat from your pocket. Don't get into the habit of pushing your dog into the sit or you will always have to do that.
Have your dog sit before he gets anything that he wants: walks, food, treats, petting, games, etc. Soon, you should see your dog sitting automatically. Then, you can start giving that command at the door.
Ignore Unwanted Behavior
This is where training becomes counterintuitive. When your dog jumps, ignore him completely. Don't knee him, yell at him or glare at him. As humans, we think this is punishment. However, this is rewarding to your dog. In his mind, at least he's getting attention. After all, you're looking at him, touching him and talking to him.
It's important to not even look at your dog when he's jumping. Fold your arms at your chest, look up and turn your back. If you have to, walk into another room and close the door so your dog can't reach you anymore.
As soon as your dog's feet hit the floor, start paying attention. Praise and pet. If he starts to jump, immediately remove attention. Repeat this every time he jumps.
Greeting Visitors
You obviously can't expect all visitors entering your home or greeting your dog on a walk to ignore his jumping, so you have to add an additional step.
Keep a leash by the door. When company arrives, clip the leash on your dog and move him away from the door. Don't let him make any contact with the visitors until he is calm or sitting.
Once he is calm, release him to say hello. This might be right away or it might be after your guests have been seated for an hour. Just keep him by your side until he's ready. If at any point he jumps, pull him back to your side and wait a few more minutes.
You won't have to use this leash forever. If you're consistent, your dog will learn that jumping is never effective. When he stops trying to jump, you can start dropping the leash. Eventually, you won't need it at all.