Question: Learning about SOA. Is it mostly decoupling by way of web services, one service provides web services to another, thereby staying decoupled and encapsulated? Thanks.

edit: that and maybe a good front end to them like some MVC design?

Answer: 
Here's an answer I provided to another question a while ago which may help with SOA principles: [Rebuild N-tier app into Service-Oriented Architecture (SOA)?](https://stackoverflow.com/questions/2349352/rebuild-n-tier-app-into-service-oriented-architecture-soa/2366496#2366496)

Also the following is an intro to SOA: <http://www.ibm.com/developerworks/library/ws-soa-design1/>

In short there's a lot more to it than just web-services, its how you make available coarse grained 'business services' for reuse by multiple systems, and how you then make calls across multiple business services to meet wider business processes.

Developing some web-services != SOA
Despite the (incorrect) selected answer I have to state that SOA has nothing to do with web services.
The "service" term is so overloaded in English, so people are getting confused sometimes.

SOA is an architectural style, a set of guidances and principles that help us model our systems as "systems which consist of other systems".
The service term in SOA can be defined as a "technical authority for a specific business capability".
SOA helps to deal with coupling between capabilities, including temporal and spatial coupling. 

As you can see, designing your system as an open set of loosely coupled and self-responsible systems (services) has nothing to do with using web services, WCF or other "cool things". You may use them or you may not use them. Or use them in one context, but not in another.

Most definitely you will NOT use web services as a communication protocol between your services in SOA because they immediately introduce temporal and spatial coupling.