Same with me.
I thought I was one of the younger ones on this forum at 18, maybe not. As for all you 15 year olds, let me tell you now, as once being 15 and having an idea of wanting to do a computer related career, and now having chosen my computer science course at uni, let me make very clear - START NOW! - and keep going, because it will pay off when you get to my age. BUT don't flaunt your 'talent' and show off to others because thats not what programmers do, thats what idiots do. Friends ask me why I do what I do, and why I don't find it boring, its hard to explain to them in words, so then you show them. BUT not by doing anything illegal or hacking school networks because that isn't how a true hacker or programmer works. They want to learn, not break, or even go somewhere where they aren't permitted to go. Learn to respect the mature rules of the programming/hacking (note: note cracking) community and you will become a respected member in years to come.
On another note, there is no better online tutorial for C++ than the official website's tutorial
and Dev C++ from Bloodshed is an excellent free compiler. Learn C++ by all means, learn to program games by all means, but as I've learnt, somewhat late, it is best to start on languages such as Python because they take away a lot of the hassle you get with the C++ and Java code, and can be used for the same thing. Whilst you use the python to teach you the ideals of programming and the formulation of functions etc etc, you then just apply the relevant syntax of java and/or c++ and you'll learn all 3 a lot faster. I've been learning to program for about a year now, on and off (A levels and such) with Java C++ and just recently python. With those 3 to start with you will be able to do a lot of things, but all things take practice. Good luck to you all and happy programming.
(p.s check out my thread on learning C++ and Java if you need any other tutorials/compilers or general info on them.)