Chromebooks are a great, inexpensive and simple solution for kids. But you may have discovered that it's not as simple to set up tools that allow you to limit and manage your kid's internet access. Hidden in the Chromebook, however, is a setting to allow creating "Supervised Users" which will give you the ability to keep an eye on your kid's activity.
John wants to lock down his internet for his kids. Leo says that the trick is to block it with OpenDNS from the router itself. Change the DNS settings on the router to block it. Then he'll need to lock it down on his system to prevent changes.