I have been doing some studies in my Masters degree covering information architecture. I really love the subject but wish I had more spare time to give it some really solid attention.
I found a couple of items on information architecture that I really enjoyed:
Oz Information Architecture 2007 (some great podcasts)
T. Scott Stromberg on wireframes and sketching (I really liked this one because I am fond of sketching out web design on butcher’s paper!)
What I really love about IA is that it cuts across a range of really interesting subjects from web design, information and knowledge management, psychology, interactive design, organisational development, information processing, and integrated visual and text-based communication strategy.
All good stuff!