ExchangeExchange.com
Yesterday I met Joel Stidley. He is a newly awarded Microsoft MVP(Most Valuable Professional) on Exchange. I learned a bunch about Joel. First he lives here in Dallas and works just down the street from Microsoft. OK I guess that's not the interesting part. He runs www.exchangeexchange.com That's cool. Go check out his site. They have some great blogs, forums, PODcast and the like.
Joel has a couple of great books.
Professional PowerShell for Exchange 2007 SP1 You can find it at Amazon I hear.
Also
MCTS: Windows Server 2008 Applications Infrastructure Configuration Study Guide (Exam 70-643, with CD) (Paperback)
It's not available yet(wait a month), but I bet it will be a good one when it comes out.
So welcome Joel to the MVP program. Sounds like this guy knows his stuff!