Voice chat would be better. All he would need is a headset with a microphone. Video chat tends to use up too much bandwidth to allow enough for the game. One or the other, if not bot, will probably be choppy.
The key is being involved. Keep the computer in the family room, and always be around. Teach him to not give out any personal info online, and to only chat (video, audio, or text based) with people you know and trust.