My son has been going with me since he was 3. Now when he was 3 and 4, you might get to go for a few hours, then you might get to go for 30 minutes. Depended on how interested he was on that particular day.
Once he was 5 he wanted to go all day everyday. I have a lot of pictures of him sleeping in the stand (box stand on ground) with me.
He is 6 now and I believe he will take his first deer this year. (With assistance of course.)
He can aim and pull the trigger while I brace the gun. Usually a .243.