Information Architecture is the act of planning, designing and supervision of the construction of knowledge that is derived from study, experience or instruction of a specific event or situation or collection of facts or data.
Wow, that's a mouthful. So what does it really mean? In it's most simple terms it means that Information Architecture, or an Information Architect for that matter, is concerned with defining the nature and scope of a web site or any other informational product is before the first line of <html> is written. Typically, an Information Architect's primary deliverable is a report or specification that defines a the key aspects of a website.
You can find some great information at the following sites:
Argus Center for Information Architecture - http://argus-acia.com/index.html - While this site has not been updated since 2002, it remains active. There are a few useful resources on the site, most notably the IA Glossary which was developed to create a shared vocabulary within the new and rapidly evolving field of information architecture. It should serve as a valuable reference for anyone involved with or interested in the design of information architectures for web sites, intranets and other information systems. The link above will take you directly to the .pdf download of the glossary. The main site can be reached through the link: Argus Center for Information Architecture.
Boxes and Arrows - http://www.boxesandarrows.com/ -Boxes and Arrows is the definitive source for the complex task of bringing architecture and design to the digital landscape. There are various titles and professions associated with this undertaking—information architecture, information design, interaction design, interface design. The site is essentially a peer-written journal dedicated to discussing, improving and promoting the work of this community, through the sharing of exemplary technique, innovation and informed opinion.
The Information Architecture Institute - http://iainstitute.org/ -The Information Architecture Institute is a non-profit volunteer organization dedicated to advancing and promoting information architecture. Founded in 2002, the Institute has over 800 members in 40 countries. This site has a lot of depth and breadth and their libary is a wonderful resource containing a selection of resources related to the field of information architecture. The collection includes articles, books, blogs, and more.
ia/ - http://iaslash.org/ - iaslash is a great information architecture news site.
IAWiki - http://www.iawiki.net/ - The IAWiki is a collaborative knowledge base / discussion space for the topic of information architecture for the topic of Information Architecture. A great starting point on the site is at the site index, I recommend starting here. However, if you are unfamiliar with the wikiweb, One Minute Wiki provides a great summary of how to get the most from your "wikiperience".
jjg.net - http://www.jjg.net/ - Jesse James Garrett is perhaps one of the most well known players in the information architecture field. He began his career as a writer and interface designer and progressed through the ranks to become an information architect. A few years ago, he started a company called Adaptive Path to help people solve user interface problems. While he does focus much of his attention these days on a myriad of UI related issues, information architecture is his primary interest. Be sure to check out his IA resource page.
Bloug - http://louisrosenfeld.com/ - Bloug is Lou Rosenfeld's weblog. Lou is considered by many in the field to be one of the two founding fathers of information architecture. Lou is currently an independent information architecture consultant.