Something that (I hope) might help you BigBird. Ian's idea of a line is a good one, however you can do the same with a club shaft.

First take your normal stance (have someone check this if necessary, it is very important). Now lift your arms to get them parallel to the ground and cock your wrists to make the shaft point to the sky, but a little to the right. Rotate 90 degrees to the right and note the position of your arm and club. That is exactly the ideal position you should be in halfway through your backswing, not further around your body. It is then just a matter of lifting the arms further to get into the top of the backswing. Make sure you keep your chin up to allow the shoulders to rotate as freely as possible.

Put a shaft (or club) about 1 foot behind your ball on the target line. Put a long tee in the hole at the top of your grip. Swing straight back and rotate your body at the same time. When your hands are at waist height, the tee should point to the shaft lying on the ground (you are then on-plane.

Hope this helps.