Destination Out strikes again- A Beginner's Guide to Free Jazz, complete with a playlist to go along, covering several critical "strains" of the music. (The links they mention are great as well, particularly the "Common Misconceptions" link, aka the "why should anyone but jazz nerds give a rat's ass."
One of the cool things about a list like this, complete with useful commentary, is it lets me take a step back and hear with someone else's ears. I love "Rated X", but would never think of it as "proto-punk noise". Pre-jungle, psycho acid-trip funk, absolutely, but punk? But when you listen through their explanation, that makes perfect sense.
I would quibble that Ornette, father of the genre, is not represented, but as I said, I quibble. Thank you gentlemen.