What is Service Oriented Architecture (SOA)? Some link that will provide you with an answer. Essentially, SOA is an architecture pattern – WikiPedi provides a great definition of SOA.
WikiPedia Definition of SOA: SOA is a design for linking computational resources (principally, applications and data) on demand to achieve the desired results for service consumers (which can be end users or other services).
Here are some other links that will help you with your studies:

There are two great books that come to mind that provide both Sales and Consultants with practical approaches to selling and delivering SOA engagements:

  • Service-Oriented Architecture : A Planning and Implementation Guide for Business and Technology
  • Enterprise SOA : Service-Oriented Architecture Best Practices