BA
There are several stances, the 2 most popular are Weaver and Isosoles (sp?).
BB described the Weaver, although the stance does not call for lowering your head, rather raising the pistol higher. If you ever saw a Steven Segal movie, he uses his own version of the Weaver.
The Isosoles is where you straight arm both arms in front of you forming an Isosoles triangle with your chest as the 3rd side.
There are pros and cons for both, use whichever works for YOU.