Mark I have been down this road five times. My final system is to use a Remington 1100 12 or 20 ga.. I have a standard weight 20 Skeet gun with a cut down stock. Load with 3/4 ounce reloads. Load only one shell and safety is always first from the beginning. It becomes second nature.

I always try to get new shooter into hitting birds early.
Take him to the skeet field and take him to station seven. Start with going away targets. After he hits several of them have him take an incomer. From there I go back to station one. Start with the incomer and then the out going bird. Keep it short and simple. After he is comfortable with 1 and 7 I add 2 and 6. Easier to add 6 by shooting a few at 6 1/2. 3,4,5 are added the next time. I save 8 until last. It is the easiest/hardest shot for a new shooter.