Microsoft describes their approach to information architecture.
1) Identify the user groups
2) Identify the content groups
3) Plan a navigation structure
4) Evaluate
An alternative approach to information architecture, focussing more on the actual building of the website navigation.
A good overview of information architecture.
Contains a list of tools for information architecture.
An introduction to a number of areas in information architecture. This article focusses on important areas.
A detailed article of the planning process. Overall similar to Microsoft's approach.