Along with the great agile bloggers at CodeBetter.com, you should take a look at three of the best agile developers/architects I know at ThoughtShapes.com. All three: Rob, Steve, and Rjae, have been presenting an in-depth look at Test Driven Development (TDD) and Domain Driven Design (DDD) at the study group I lead each month: Boston .NET Architecture Study Group. The first two months were on how to get started with TDD and testing the UI. They will be covering how to test the database access calls without a database over the next one or two sessions. The sessions have been inspiring, educational, and incredibly well done.
So, add these guys to your blog roll -- you will be glad you did. Some examples of their latest posts: