If you are on this page then it is very sure that you are beginner to Mac OS X Snow Leopard and about to fade up now because your past MS-windows experience is not allowing you to use this freely. If you are fade up with the way how your Mac puts layers of windows of similar program on each other and there is no easy way to handle this situation, and then it becomes difficult for you to manage it then here is the solution.
If you have multiple windows open of a same program in Mac and want to switch easily between then using shortcut keys then
Press Command + ~
(For beginners, let me explain little more that you need to press command key on your keyboard along with the ~ key. This ~ key can be found just below to escape key in the top-left corner of your keyboard.)
As many as times, you will click it it will work like internal tab and will switch between the same program windows. Try this and I know you will take a deep breathe 🙂
So does that make your life easier 🙂