A couple of days ago I received a copy of a brand new book called "Cool Mac™Sounds" by Craig O'Donnell.
I don't know if it's because I'm favourably prejudiced by seeing so many flattering references to my own "cool" stuff, but I found the book to be an excellent reference on the Mac sounds scene. And its general look and feel is definitely "way cool"!
I would highly recommend it to anyone who - like you and me - has more than a passing interest in getting the most out of sound on their Macintosh.
It's published by Hayden (ISBN 0-672-48523-0), comes with a 1.44 Meg HD disk full of sounds and sound utilities, and costs US$19.95.