I would like to give you two real simple drills that will help you understand how the arms and body swing and how the body swings the arms and how they work together.
Drill #1: Hands Apart Swing Drill
One of Curtis Strange's favorite drills during the 80's is he used to take every practice swings with his hands apart. By practicing with his hands apart he always felt his left arm on the inner force and his right arm on the outer force; therefore, he always maintained centrifugal force.
He would always take practice swings with his arms apart because it is natural with the hands apart to swing the club correctly. Whereas most people as soon as they put their hands together the left arm takes over and pulls. This causes them to lose the outer force and they loose the feeling of what we want. The split grip is really a great drill for you to use.
Drill #2: Sternum Position
Another drill that we like to have our students do in order to understand how the body works is to set up to the golf ball and just pretend that there is an extension from the butt of the club to the sternum. Then they take the club back and then swing to their sternum and then forward to the finish.
The Correct Swing
We find as long as they do this they are always keeping their club in the center and they are always maintaining the triangle all the way through the swing. This is the best way in the world for them to feel what we want them to do. It feels smooth and really makes you swing right. When I do the club in center drill look how my shoulders coil and my right side releases. It is one of the best drills I know about and if you do it you can really learn to play golf.