Using Multiple Displays:
After connecting a laptop to a projector (using Apple TV or hard wiring with a VGA or HDMI dongle), you will have two choices for showing your screen (the below choices will only appear after the laptop is connected):
1. Mirror Display - Mirroring will show exactly what is on your laptop screen to the projector. Select Apple (top left) - System Preferences - Displays - Check Mirror Displays
2. Separate Screens - When using separate screens you can drag windows from your laptop screen over to your projector screen. This is helpful when you need to work on your laptop while showing separate images on the projector. Select Apple (top left) - System Preferences - Displays - Uncheck Mirror Displays.
Your Mac screen is now extended. Click and drag what you would like to display onto the projector (typically to the right). Anything you do on your laptop will not be visible on the projector.
Remember to check Mirror Displays again when you want your Mac screen to be visible on your Apple TV!
QuickTime Screen Recording:
With OS X 10.6 or later you can now do screen recordings easily on your laptop. Open Quicktime application and choose File > New Screen Recording.
Thanks.