Before you start jailbreak, you need to do the following to your iPad.
1. Make sure you upgrade the iOS of your iPad to 5.1.1
2. If you have Passcode turned on, disable it.
Here is the detail steps:
1. Download Absinthe Jaibreak tool Windows version or Mac version.
2. Unzip the download file absinthe-win-2.0.4.zip to any folder. This folder contains the following file.
7. Once it is done, you should see the following message "Done, enjoy". That's it! You iPad is jailbreak.
Note: If you did not see the "Done, enjoy" message, this means the jailbreak fails. Don't panic, it happens to me first time. Just re-plugin your iPad and do the above steps again. It works for me second time.
If you experience the Sandbox problem in Game Center or in-app Purchase, please visit my post on how to resolve:
How to fix the iPad Sandbox problem (This is not a Test User account error)