I used to be a pretty avid player myself, but sold all my good cards years ago.
My six year old found all my commons and stuff I couldn't sell, and has become addicted. He's pretty sharp for a six year old....but he's still only six.
I wouldn't trust him with anything really good, though I might be tempted to trade a GU or nice rookie for a Jinzo (he likes machines) or Mirror Force (which i would sock away in case he's still interested when he's a little more able to take good care of them).
Anyway, PM me if you've got cards lying around and tell me what baseball or football you collect. I have much much more good baseball base...