Every thing ASP.NET...

Introduction to ASP.NET

You'll find several helpful articles on ASP.NET on the articles page here but maybe you'll find this article the most helpful if you are new to ASP.NET (especially if approaching from a PHP point of view).

Understanding the PipeLine

I consider it essential information to know the flow of a Request pipeline (before, during, and after a page is rendered), and the LifeCycle of a Control. You'll find that kind of information here:

1. Request PipeLine
2. Control LifeCycle