You can, make sure you update your iPad to iOS 5, and updates your Apple TV to the latest software. Once done, connect both to the same WiFi then double press the iPad home button (bring up multitasking bar) and swipe to the left to reveal the brightness and volume stuff. There should be an AirPlay icon, touch and there will be an option for AirPlay mirroring.
Yes you should be able to share anything on your iPad as long as you are fully updated. Just click the home buttom TWICE and then swip the toolbar all the way to the right where you see a apple tv symbole and turn MIRRORING ON ! and it should be mirroring your ipad on your TV . To turn it off you do the same steps.