Modern technologies certainly benefit many golf lovers and professionals. It is very helpful to visit a "good" - means good golf teacher and let him/ her to do a video analysis of your golf swing. It will help you understand golf swing faster and realize whatever flaws with your golf swings. It is usually ran from 50 -100$. However, if you are taking class with golf professional teachers. 8 out 10 of them will have the equipment to do this for you, so you just need to pay the regular instruction fee.
Caught this video clip on google video -- Steve Miller's video analysis, I think he is a beginner who can hit the ball well, but not consistent. Not meaning to point anything incorrect that he did, this is just a clip that I think that can help people understand the mechanics behind swing. The teacher's instruction is pretty clear and right on the money, I like it.
http://video.google.com/videoplay?docid=-5084105507160185261&q=swing+analysis