When you are about to give someone some news which you know will please them, you can say that you are pleased to tell them the news or that they will be pleased to hear it.
In official letters, people often say they will be pleased to do something, as a polite way of introducing what they are going to do or inviting people to do something.
If someone seems very satisfied with something they have done, you can say that they are pleased with themselves, especially if you think they are more satisfied than they should be.