Just the fact that your thinking about it is a leg up. If they see you hunting and having fun and being successful that's a great start. I started with a small bow in the back yard and a BB gun. Let them shoot some stuff. I used to eat every song bird I ever shot. I'd steal matches from the house and shoot chickadees and breast them out and cook them over a pine fire. Small game hunting came next with a single shot 22. Let them know they can shoot what they want but be prepared to eat it. It has to be fun and there has to be excitement. My family used to trap. It's a great way to learn the habits of the game your after. You won't hold a kid whose bored. Who doesn't love to shoot into the water. My step dad used to take my brother and I to the dump(target rich environment) just to shoot. Take them on plinking walks so they can shoot leaves and stumps and chipmunks and just shoot, and if you happen into some deer sign well that's a bonus. Teach them the art of sitting, and looking, and listening. But in short bursts that get longer over time. Let them track stuff. We used to fish the creeks but spent half the time tracking raccoons and getting soaked and muddy. Bring some food and snacks, and you hump the extra things so they can be comfortable(plenty of ammo). Sit in the middle of the woods or on a creek bank and split a pb&j with the boys. Get them each a cheap set of camo and if their into it paint their face a little. Try to think like a kid and do the things you remember liking as a kid. Impart the rules, safety, fair chase, wanton waste, but don't lecture them. Bring that stuff up as a matter of fact a little at a time along the way. Let them see you pick up some trash and put it in your pocket but don't make them do it all at once, it can't turn into trash day. The little peckerheads see more than you know. But the second it starts to turn into a drag your fighting a losing battle. All that drudgery can come later. I call it drudgery, but it's the real work of being a law abiding successful sportsman and steward of the land. Let them be kids. Lead by example. Don't let them take short cuts. and 0 tolerance on unsafe acts. Let them know that it can be dangerous and they need to act responsibly, no horsing around when your carrying a gun. Just writing this brings me back to when I was a kid starting out, it's the best memories. Good luck and be patient, Rome wasn't built in a day.