Computerworld has a great article that provides step-by-step instructions for setting up the service and it is very easy to set up. In a nutshell, you go into the Mail, Contacts, Calendar settings and add a MobileMe account by providing your Apple ID and password. The Apple ID and password is what you setup at the Apple Store when you bought your iPad or created when you turned the device on for the first time. This is also the same credentials used to buy things (movies, music, apps, tv shows, etc) from iTunes. If you don’t subscribe to MobileMe, the settings default to the "Find My iPad" option.
After you enable the service, go to www.me.com to confirm that it is working. You log in using your Apple ID and password, and you will see the location of your iPad displayed on a map. In addition to seeing the location of your iPad, you have the ability to lock it, send a message to it, send a sound to it, or wipe your data from it.
Once setup and activated, the iPad can be located from any Internet connected device like a PC, Mac, desktop, laptop, smartphone, iPhone or another iPad. As long as you are able to connect to the Internet, open the web site and have your iTunes or App Store ID and password, you can locate the device and send the below commands.
The lost iPad has to connect to the Internet to be located. If the device is never connected to the Internet it can not be located. If it connect via the 3G service or the WiFi service, it can be located with the "Find my iPhone" service. You should always configure your iPad with a passcode and set it so that locks after a certain amount of time. If a person has your device and it is unlocked, they can erase everything (including the settings that make it trackable) and then you may never locate it.
Finally, if you own another iOS device, you can install the free Find My iPhone app that you can use to see the location of your iPad on that device.
The Play Sound option is useful if you lost the iPad in the house and what to listen for a sound to locate it or use to tell your spouse it is time to get off the device.
This is a free feature you should signup for and activate immediately after purchasing your iPad. Make sure you test it before you need it, somewhat you have experience before a real world opportunity arrives. So being prepared will keep your asking, "How do I find my iPad if it is lost?"
Here's to hoping you never have to use this knowledge beyond preparation and practice. Now where did I leave my keys?
By Carl W. Brooks