In the 1980s, an IBM researcher named John Zachman wrote a paper entitled "A Framework for Information Systems Architecture" and gave birth to the ideas around Enterprise Architecture. Zachman's framework is a table with columns that relate to the what (data), how (function), where (network), who (people), when (time or schedule) and why (motivation or strategy) aspects of the architecture and rows that walk down the scope continuum: Context (partners), Business Model (owners), System Model (designer), Technology Model (builder) and Detailed Representations (subcontractor).
Zachman, along with Samuel Holcman, created that Zachman Institute for Framework Advancement. The institute's web site contains some free white papers (you'll need to register) and offers to help you figure all this out for a fee.
I like the matrix because it gives you a field of play, so to speak. I imagine that if you study it, you'll find two, three, five, or ten of these squares you think you have a pretty good handle on. That tells you where to concentrate you focus and gives you some context. One of the tough parts of enterprise architecture as defined by the federal EA project management office or the state CIOs at NASCIO is that there was so little context that people have a tough time finding a hand hold and figuring it out. There's lots of places in the Zachman framework to grab on and get started.
That said, FEAPMO and NASCIO are trying to define processes for large organizations to create an enterprise architecture. An EA is nothing more than a detailed plan for how IT will be managed in the enterprise. Detailed enough to ensure interoperability and backed up by reasonable policies. As you look at the Zachman framework, pick a square at random and ask yourself: "what plans, policies, and procedures does my organization have in place to make sure we do the things covered by this square consistently and in accordance with best practice?" If you'd like some help figuring this all out or just talking about how to get started, give me a shout.