Hi, everyone. I'm 33 years old and computers are a hobby for me. I've never studied computers at Uni or worked professionally with them. I learned BASIC on the TRS-80, then 6809 assembly, then got an Amiga and learned 68000 assembly. In high school I dabbled in C, C++ and Pascal. I'm interested in using my programming skills to program AVR microcontrollers, maybe write a Wikipedia bot, and hopefully make myself useful to a Linux project or two one day.
Recently I made the decision that I wanted to learn one language really well, so that instead of kinda-sorta knowing programming, I could become a guru in one language. I chose C99. I have read K&R 2nd edition from beginning to end. I've also read Sam's Teach Yourself C in 21 days, which covers the same material.
So where do I go from here? To become a guru C programmer, what do I need to know now?