Resources for Using a Mac
Tour the Mac Interface - Apple Website
On Windows, I use to.... - Apple Website
Connecting to AppleTV
Be sure you and the AppleTV are on the same wireless network SSID.
Drag from the bottom of your iPad sceen to access the tools.
Click on AirPlay.
Choose your AppleTV device and make sure that Mirroring is ON.
Both sound and image will come across the HDMI connection.