This is a good video. It illustrates the most commonly taught method of shooting in the US today. It does two things better than other videos I have seen on this subject. The first is a mechanical illustration of how archery injuries occur, which was easy for me to understand. The second is a demonstration of incorrect methods of shooting the bow.
Modern educational theory is to stick with positive messages; i.e., positive reinforcement of things that the teacher wants the student to do, when the student does them. This is fine, but if all someone does is give me positive reinforcement, it is difficult for me to recognize when I am doing something wrong, or recognize what my students are doing wrong. Clearly, modern educational theory is a reaction against a time when mainly negative reinforcement was given, and justifiably so. But a balance of both approaches, as is illustrated in this video, is the best approach, I think.