How to train a job to stop barking

In the video Jim Leske says that it is very bad to pet your dog and reassure it that everything is okay. That only teaches them to keep barking. Jim states thats you should use a no or stop in a stern voice. Another instance is where you come home and your dog is on the door barking. If they bark and you let them out it only trains them to bark to get out of the house. He again says to use a stern no to let them know not to bark.
This video is very educational. I never knew that letting my dog outside for barking at the door would train it to bark to get out. From now on I will use my stern no voice and my dog will not bark when I do not want it to.