Training for 11 year old

I came across this video on youtube. It's a 11 year old girl who has been trained by her dad. This video has three parts and there is even one where she field strips an AR15 in 24 sec. It's very impressive. My oldest son is 5yrs old and I'm just wondering at what age would be appropriate to start to teach him how to shoot. I've already educated him on gun safety and on what to do if he ever see's one without an adult around.