instead of trying to type my rambles at this hour (4:00a.m.) i'll give you a link that will put a lot of valuable info at your fingertips....
http://www.sportshooter.com/improving/
Do yourself a favor and print of the correction target. This is a valuable piece of equipment that should go with you to the range. We use it in the Police Academy and also at our qualifications and you would be surprised how well it tells you what your doing wrong.
As for stance.. well that's a personel thing. Each person will find one that is comfortable for them and works best for them. I prefer the weaver stance myself but try them all to see which one you like best.
"A vote is like a rifle: its usefulness depends upon the character of the user."
Theodore Roosevelt
http://tscott.fws1.com
ONE NATION UNDER GOD!