Dave Orchard: SOA Principles
This document provides a technical description of SOA and what it means for Architects and developers. Readers should have some familiarity with current technologies such as Web, XML, and Web services. This document provides a view of SOA as a broad set of architecture, design principles and choices used in building distributed systems. In essence, this document views SOA as a few core principles and a set design options or “knobs” that are set differently for each particular application depending upon the features required.
No time now, but this definitely merits a very close look.