I guess along with what others have said about how ready you think your son is, the the other question we can't answer is how old were you when you got your first knife? Also, is it going to be all his, or "his" and has to get it from you? Is he going to be allowed to carry it in town?
My grandfather and my biological father's father never agreed on much, but they did think I needed to know how to use a knife. My first "all mine" knife, that wasn't a loaner or anything like that was a Vic Huntsman. Still have a wicked scar on the back of my left thumb from having it slip while closing it, but that was the only time it ever bit me. Don't have the knife anymore though, it went missing in a move.
My brightest idea is to give him an IOU-type card, and take him to a good sporting goods store where you've already selected a few items that are in budget and inside your ideas about size, and talked to people there so they know that nothing strange is going on when you bring him to see what fits best in his hand. And if he gets exposed to a smaller, local sporting goods or gun or climbing store where people can go in and just shoot the breeze with someone behind the counter who is clued, it can only be a good thing.