Been really is one of the greatest unofficial mentors of the greater development community
I don't know network programming very well, but what little I know was learned from Beej.
It's actually been quite rare in my professional programming career that I've had to use any of these things that I learned from Beej but... when I needed them.... I knew where to look and, knowing even just that, it's made me look like a wizard. Honestly, I can't see a 'donate' link here, but I really feel that I should.