Getting Started With IA64
Mailing lists you should probably be subscribed to.
The Intel documentation can be found at http://www.intel.com/design/itanium/documentation.htm
You will probably want to keep the Software Developers manual volumes 1,2,3 around as references, and read the Software Optimization manuals.
Locally, many people hang out in #keg on om.disy.cse.unsw.edu.au.
Externally, the #debian-ia64 channel on freenode.net is probably the most populated, but due to time differences is usually very quiet.
The canonical book is
The Mosberger/Eranian book : IA-64 Linux Kernel Design and Implementation
Other interesting books
Understanding the Linux Virtual Memory Manager, Mel Gorman
- Linux Kernel Development, Robert Love
The Gelato@UNSW WiKi contains a wealth of information (which you must know about if you're reading this!)
You can go via the library for access to Safari which contains many good books.
Getting and building a kernel