Though built on similar principles, SOA is not the same as Web services, which indicates a collection of technologies, such as SOAP and XML. SOA is more than a set of technologies and runs independent of any specific technologies.

Migrating to a service-oriented architecture, Part 1
This is the first in a series of papers intended to help you better understand the value of a service-oriented architecture (SOA), and to develop a realistic plan for evaluating your current infrastructure and migrating it to a true service-oriented architecture.

Realizing a Service-Oriented Architecture with .NET
This article is meant to be a practical discussion guide to building a .NET application in a service-oriented architecture.

Service-Oriented Architecture Explained
This article describes the essentials of SOA.

Term of the Week: Service Oriented Architecture
This article from Developer.com provides a quick look at the principles behind SOA and the benefits it gives.

Tips for Designing a Service-Oriented Architecture
Some core design principles to help concoct a plan to design an SOA.

Web Services and Service-Oriented Architecture
This site will help you get started with Web services and service-oriented architectures. It features free articles, product listings, and services that can be used to develop a service-oriented architecture.