How to Capture the Screen or Window as an Image
Built into Mac OS X are handy shortcuts for capturing the screen.
That ^ character indicates the “control” key, the up-arrow means the shift key, and the curly thing is the “command” key.
I use control-cmd-shift-4 90% of the time to capture a desired area; a cursor appears, click and drag to select the desired area, which is then placed on the clipboard as an image.
To neatly capture just one window, I generally use Grab, found in /Applications/Utilities.