SOA in the Real World Book from Microsoft Architecture Group
Released a couple of weeks ago,
SOA in the Real World is a good summary of the guidance that Microsoft has been putting out for the last 5 years. As my main task in the current gig is the writing a document of integration stategy and then working with the development team implementating web services for the first time, the e-book is a timely helper with this task. I'm still working through the first few chapters, but it looks promising.