I recommend you start with the Nock tutorial:
The build instructions in this file are out of date, use the ones from the Arvo chapter. Also, probably the best short overview is the header comment in the Hoon compiler:
Also don't miss the video: https://vimeo.com/75312418
After watching the video I'm legitimately interested in more than the language. You've got some cool ideas going on there. I'll be emailing for a 32-bit destroyer in a second.