Maybe a long shot ... O_o;;;
Here is the problem: I have a nephew.
He is 12. His favorite things are Star Wars, fighting games, when he was younger he liked Pokemon ... he says he wants to work on games when he is older. XD How would he even know now, of course. But I wish I could buy him something both instructional and fun. Nothing that remotely feels like work.
I was 15 when I came in to something I felt passion for. (comics) So now seems like the time to try and introduce him to things he might like.
Most all the designers I met in undergrad started the way my nephew is now. They just liked gaming and started imagining games and then went to school for it.
Suggest anything on any system.
A book is probably not a possibility unless its graphics heavy and very engaging.