On Raymond Hettinger's advice I picked up a copy of "The AWK Programming Language." At 200 pages it makes "The C Programming Language" look like a door stop by comparison. I'm told Chapter 2 is especially good. Chapter 2 is 50 pages out of that 200.
Up til now I've been modeling my writing on Stevens and specifically "Advanced Programming in the UNIX Environment." That book truly is a door stop and I've consulted it too many times to count. Need to write a quick and dirty TCP/IP server? It's in there. Can't remember how to properly fork a daemon? It's in there (don't forget to fork twice!) It is an incredible achievement for a computer book to still be useful over 15 years after it was published.
Raymond also says he has checked in a bunch of optimizations. I'll have to 'svn up' and maybe write about them here (I say that just to increase the likelihood of doing it).