You'll be surprised by the sheer amount of information you can find on architecture on Microsoft web site. Below are some of the good resources...

Skyscrapr is your window into the architectural perspective. Solution, Infrastructure, Industry, and Strategic Architects create visions, develop plans, and work with developers to implement solutions. http://www.skyscrapr.net/

ARCast Keeping up on the latest trends in architecture is hard. With new products and technologies constantly flowing from Microsoft you need someone who can cut through the fluff and get to the bottom line. Listen in as Ron takes on the tough topics with an attitude. http://www.skyscrapr.net/blogs/arcasts/default.aspx

MSDN Solution Architecture Center http://msdn2.microsoft.com/en-us/architecture/default.aspx

The Architecture Journal is an independent platform for free thinkers and practitioners of IT architecture. New editions are issued quarterly with articles designed to offer perspective, share knowledge, and help you learn the discipline and pursue the art of IT architecture. The Architecture Journal reaches over 30,000 subscribers worldwide. Click here to receive a free print version. http://msdn2.microsoft.com/en-us/arcjournal/default.aspx

If you want to receive ARC news as soon as they are published, just subscribe to this RSS feed!  http://msdn.microsoft.com/architecture/rssArc.xml

I came across quite a few interesting articles and would like to share with you...

A Business-Oriented Foundation for Service Orientation http://msdn2.microsoft.com/en-us/library/aa479368.aspx

Software + Services: An Architectural Perspective http://msdn2.microsoft.com/en-us/library/aa905319.aspx

Architecting Service Broker Applications http://msdn2.microsoft.com/en-us/architecture/aa964144.aspx

Federated Identity: Scenarios, Architecture, and Implementation http://msdn2.microsoft.com/en-us/library/aa479079.aspx

Pragmatic Architecture: Layering http://msdn2.microsoft.com/en-us/architecture/aa905336.aspx

A Better Path to Enterprise Architectures http://msdn2.microsoft.com/en-us/library/aa479371.aspx

Alchemy Business Overview http://msdn2.microsoft.com/en-us/library/bb220797.aspx

Architecture Strategies for Catching the Long Tail http://msdn2.microsoft.com/en-us/library/aa479069.aspx

Office Business Applications: A New Breed of Applications on the 2007 Microsoft Office System http://msdn2.microsoft.com/en-us/library/aa479072.aspx

The Evolution of Architecture with Martin Fowler http://msdn2.microsoft.com/en-us/library/aa983296.aspx