HEY! My first post! Anyways, My little girl is 4 and I started teaching her about never touching a gun without dad or grampa there and all that. She is now slowly starting with my pellet gun in my woodshop. One or two shots at a time so she does not get frustrated. Safety paramount. "Range Safe", "Range Hot" stuff, safety glasses and all. My wife grew up with guns all over the house with absolutely no issues. They were taught that if they wanted to check something out, just ask. She shoots pistols very well when she does it some (that whole practice thing). Start them very early with the dialogue, then move them to BB/Pellet when you think they listen good enough, then the next step is real guns when they really listen good. Teach them that pellet guns are dangerous and can kill too, but firearms are even more dangerous if you are not safe. Around 5yrs I think is about average, but it VERY much depends on the listening skills. I am not ready for my girl to go firearm yet. She listens pretty darn well, but I think end of this summer is going to be right.