So, as a way of introducing my nine year old nephew to wargaming I've picked up some dirt cheap Space Marine plastics for him and I've been teaching him how to paint. We've actually played a game or two now so I've started creating a "Kiddiehammer" codex for his marines and my Eldar.
The goal is to approach gaming and strategy with baby steps. Using dice similar to Hero Quest etc. will get my nephew up and running. Eventually I'll cease telling him what dice to roll, etc. and let him consult his mini-codex etc. He has taken to everything really well so far.
Making the "KiddieHammer" codices. Simplified stats using the combat dice I posted earlier.