You must take backup of iPad frequently, due to any reason your may need this backup to restore on your iPad later. If you want to backup iPad 2, follow the given instructions below. You can use same method to backup iPad 1 as well.
How to Backup iPad 2
First connect your iPad with computer using data cable and run iTunes on your computer
Your iPad device will be listed in iTunes under “Devices” section
Right-Click on your iPad device and select “Back up” option
How to transfer iPad to iPad 2 (All data and settings)