It really isn't that hard to pick up enough programming to build a simple CRUD app if you are dedicated enough. One great resource (although time-intensive) is Dev Bootcamp, a program based in SF that will teach you how to program in 10 weeks. I can't speak highly enough about Dev Bootcamp -- my youngest brother went through the last class with barely any programming knowledge coming in and at the end of it landed a full time programming job at a consultancy.
Alternatively, the classic method always works: just start trying to build something and google until you figure out how to do it.
Exactly how I learned as a 10-13 year old: I wasn't writing very much code from scratch, but rather gluing together large swaths of copy/pasted example code from the internet. It was messy and nasty, but by bending other peoples' code to do what I needed I slowly came to understand it.
I would guess a lot of hackers on HN started young and already have several years of experience by the time they hit college. And by that point they might not even need to choose to study CS, instead rounding out themselves by studying other interests.