In my opinion squirrel hunting is the best way to teach kids to hunt. Plenty of action, you can move around, you aren't going to want to put him up for adoption when he blurts something out and spooks everything within a mile... Seriously 5 is pretty young for deer hunting. Kids attention spans are pretty short and the last thing you want to do is make it a bad experience for him. You have to realize that if he is with you the day is about him and not about you hunting. That means if it's prime time and he's bored you are done. If he would rather wander around and hit trees with a stick then let him. Make it fun for him. Take him scouting, take him when you put up stands, take him on a recovery but if you want to hunt grab the .22 and a pocket full of snacks and chase some bushytails. Even then you are more likely to spend a day plinking pine cones for the fun of it. In the end you will be more likely to plant the seed and have a hunting buddy for life.