Anthony Ferrara has posted what he calls a beginners guide to MVC for the web, a tutorial that introduces to you the basic concepts behind the Model-View-Controller design pattern and how it should fit in with the SOLID design principles.
There are a bunch of guides out there that claim to be a guide to MVC. It's almost like writing your own framework in that it's "one of those things" that everyone does. I realized that I never wrote my "beginners guide to MVC". So I've decided to do exactly that. Here's my "beginners guide to MVC for the web".
He starts with his first lesson, his most important one really - you don't need "MVC" (the concept, not the pattern...he notes them differently). He then gets into what the MVC pattern actually is and describes each piece and how they fit together. Following that, he talks about "MVC" as a concept and how it's different from MVC, the design pattern (hint: the pattern describes one implementation of the MVC ideals). He talks about the role of state in the MVC structure and how the implementation of the MVC idea is slightly different in the various "MVC frameworks" out there.
There is a very useful lesson that MVC brings: Separation Of Concerns. Meaning that you should separate different responsibilities into different sections of your application. Separation of Concerns is a necessary step in dealing with Abstraction. Instead of latching on to MVC, latch on to abstraction. Latch on to separation of concerns. Latch on to architecture. There are far better ways to architect and abstract user interaction for server-based applications than MVC.