Well, heres some information:
Screenshot Guide
Screenshot Program (Instead of Using F9 in the game - it allows you to save pics where you want)
In the game - to "window" the game you do it under Options (F7), then under the Graphics you can select Full Screen (a checkmark) or remove the checkmark and select the size you want.
Not sure about the steps on the Mac, but I'm sure the information above and a few others have some input