I voted on the 12-14 years old only because I wasn't sure if you ment for them to legaly hunt with their own weapon. Or if you ment to come along with you and watch. I took my oldest son out when he was 5. I had shot a doe and knew where she died. There was still 2 hours of light left so I got on the cell phone and told my wife to get him ready to help find the deer " that I couldnt find". I picked him up and showed him where I shot her and he followed the blood trail about 60 yard to the deer. He will be 14 this Nov. and to this day he still thinks I never would have found her without his help. So take them in the woods when you feel they are ready. Be smart about it, go for short trips when they are young, only dry and fairly warm weather so they will be comfortable. And last but not least be very patient and dont expect to see alot of deer activity when they are really young
. And hopefully you will turn them on to hunting!!!