depending age, stature and ability start with a 22 atleast and keep going from there. dont jump to fast as in not from 22 to 12ga. get them used to shooting with something like a 22 and get them to be accurate. then move only when you and the child feel comfortable. teach them to use both scopes and iron sights. i think kids and young adults both are neglecting the simplicity and accuracy of iron sights due to lack of being properly taught.