Consistency is the key to house training a dog. This not only applies to you but rather to everyone in the household.

Everybody in the house has to treat the dog the same way. If you are trying to teach the dog not to jump up when someone comes in, everybody has to work together. Everyone must use the same techniques and use the same command words. It is important that everyone turns their back to the dog and ignores him the moment he starts jumping. Tell the dog to sit. Once he has settled down, praise the dog. Unfortunately this will only work if everybody follows this. If just one person allows the dog to jump on him or her then the poor dog is getting mixed signals. And it will take a lot longer to train the animal.