There is already some information out there that I have found and used, here are the most useful ones I have found so far.
Western Digital's own forum This is an unmoderated site and has quite a lot of information scatterd across a few threads but it is not very easy to read and follow.
Martin Hinner's site A personal site with some useful tools to gain access to your drive using SSH. This is accomplished by "upgrading the firmware" with a simple shell script.
Mario Pascucci's blog Another personal site detailing how to start with a clean hard disk and install debian.
Linux from Scratch A useful site to get the basics of Linux installation process for those new to Linux
Mark's Blog: Welped.com Some blog entries on hacking MyBook (including setting it up as PHP web server)
Charles Hayden's site Notes on setting up MyBook pulling together information from various other places.
NAS-Central A place where all hacking communites come together
Compile/install ncurses, lynx, vim and samba Some tricks to compile working binaries from current samba sources.