Originally Posted by Unforgiven
Yes, I would put it in airplane mode and then manually turn on WiFi so he doesn't accidentally call 911. It is also a good idea to pin lock purchases and in app purchases in the Play store. It is under settings. In there you can also set a content rating for apps in the Play market, which is also a good idea.
My 5 year old ran my retired D2 for a long time until I gave it away. Now he has his own Nexus 7.
Could I just create him own gmail account that has no credit card attached to it, so that he could only download the free stuff.