Advice needed

I’m an experienced PHP programming and I have some knowledge of AS3 but I feel that some things that I’m doing are a bad practice. I believe this based on proper structure of other languages.

I find myself using the document class kinda of like my main loop. In that, I contain all of my processes inside of it. I don’t know too much about AS3 OOP, but it seems like this is bad practice (even in simple applications). I know in PHP OOP you would include your classes, then just do your processes in the main file using those classes and its methods. I assume the AS3 equivalent for the ‘main file’, would be the stage?

Links to tutorials explaining the dos and don’ts of AS3 OOP would be appreciated, as I’m getting back in AS3 and I want to do things right this time.