We're using AirWatch Mobile Device Management (www.air-watch.com) to do this with about 100 Android tablets. They have an optional Secure Launcher app with basically turns the tablet into a kiosk device, limiting it to whatever apps you specify be allowed to run. It blocks Settings, which is where users can cause havoc. You don't have to use the Secure Launcher, however. With only one tablet this may be overkill. If you have plans to use 10 or more, you should consider it.
What I would worry about is files saved on the device that are inappropriate for children to see. There are apps out there to capture and re-image the tablet but the last I checked they required rooting the device. Research the Google Play store for these but be careful. Otherwise you have the factory reset option, but you'll have to re-setup the Wi-Fi , etc.
