The Agile Alliance homepage is the best starting point for anyone interested in learning more about agile software development.
In Agile Architectural Modeling, I describe a collection of agile strategies for architectural modeling
Agile Enterprise Architecture describes techniques which enterprise architects can follow to support agile development teams effectively.
New To Architecture provides a collection of links to articles describing architecture modeling strategies.
Agile Models Distilled provides links to overviews of a wide variety of models at
The principles of Agile Modeling v2 are described here.
The practices of Agile Modeling v2 are described here.
Check out the Agile Modeling mailing list.