I'm learning C programming (I chose C because I want to program MCUs as well).
I already learned the basics, but now i want to learn how to program GUI and audio,midi recording,processing.
But I don't think buying a 400 or 1200 pages long book would be the best option because:
I find that i can learn much faster from commented source codes than reading pages of definition with a short abstract example code. The result of such method is that i know what it does, maybe even why, but i don't know how to use it (or why would I use that instead of something else) in a real program, thus i forget it.
I don't think I'm alone whit this, so i think making a good collection of richly commented source codes of various programs would help a lot of people.