1) Start with sailplanes. Solo at 14 (if he is ready for it)
2) Find an instructor that is a school teacher or retired school teacher (they
will have a better understanding of the methods that will work best with a
young mind)
3) Navigation... give specific directions for the information you want. Begin
by setting him in front of the computer and walk him through the process. Walk
away and come back, ask how things are going, heap lots of praise on what a
good job he is doing, etc. When he says he has everything, sit down and explain
what you are looking for and why. If you see something that raises a flag that
you want to explore a little more, explain why and sit down at the computer
again and walk him through the source of additional information, why/what is
different and helps you in your decision process. Talk about NOTAMS, the
information they contain and why you need to know it.
Preflight and inflight...
Map reading... review the route, looking for "obstacles" (MOAs, towers,
Restricted Areas, etc), don't let him peek at the big moving map display, make
him do it the old fashion way, match the ground features with the map. Teach
him the pencil and paper math, (wind triangles) before you introduce the whiz
wheel or calculator. Work W&B/CG calculations.
Introduce tasks one at a time on different flights to avoid information
overload. Back off at the first sign of frustration.

Come to think of it, Margie would make a really good instructor for your needs.
She already knows this stuff. She could write a sylabus.