When I was that age, which was about 10 years ago, I built my first computer. I was also tinkering with the infamous 'bread board' circuit test beds and random resistors and chips that I could get my hands on.
I would have loved to have a subscription to something so amazing as the Make Magazine at that time. It has some amazing bits in it about almost anything that I could ever have wanted to do or make. Besides that, it would have allowed me to find out about some crazier things to do in your own kitchen or garage to make something fun long before I would have played with it at school or college.
All in all, I can't recommend Make Magazine highly enough.
How many Bavarian Illuminati does it take to screw in a lightbulb? Three: one to screw it in, and one to confuse the issue.