If you need to take a screenshot on your Mac, it’s super easy, and the built-in tools usually get the job done great. Here’s how to do it, super easy. For a full-screen screenshot, press Command-Shift-3. You’ll hear a camera shutter and a new image file will appear on your Desktop. It’ll be named Picture 1. Keep taking shots and you’ll get Picture 2, Picture 3...
SweetMacTips #5 - Keyboard Shortcuts on Vimeo. Best to watch it full size. (via Vimeo)