[F8] Class Structure

I have had no luck in finding a tutorial, forum thread, or even book, that explains how to structure the class "skeleton" when creating an RIA. I want to create a website that is a 100% Flash enviroment. As I create each part of the site, i.e. navigation, php interaction, content format..., I find that I am going back and editing several class files, dropping functionality from them that I am covering with a new class. I am sure that there is some standard structure for class files in a full-Flash site, and I'm just not aware of it. I don't need a full tutorial on every detail, just a basic class structure. I am just tired of writing overlapping code. Also, seeing some structure examples would help me figure out the order of events I need to follow when I initialize the movie.

Oh, and maybe a basic structure for the base .fla also. There is a standard structure for writing class files, why can't I find one for writing a basic Flash website?

Any advice would be greatly appreciated. I am sure there are plenty of techniques better than the one I am using that would save me lots or rewriting code.
Thanks.