Seeking advanced debugging and analisys advice for .net applications

Question

Hi Everyone,

I am a recent graduate college student working for a successful software company doing up to level 3 support for our applications.  I will be accepting a new position starting next year where I will be doing more in depth analysis and given full code access to help triage and perform maintenance as well.

Our software is mainly written in c#.net/asp.net  with WCF services, some silver light, 1,000 + table sql db and web services. 

So for those who have already done the above or currently doing so, I am looking for some guidance to make me the best I can be in my position.

I am currently reading the CLR via c# which seems to be a good book so far.  I have been dabbling with wire shark and windb as well but am still a novice to say the least.  I am looking for more of an "under the hood" approach as opposed to coding examples since I believe that in order to troubleshoot/debug you should know what is and what is supposed to happen.  

Most of my coding I learned in college was console based so I am week with GUI and windows forms.  A question I have off hand have to do with trouble shooting an application that is freezing or hanging.  I am well aware that there are an infinite amount of scenarios that can cause such behavior so bear with me as I try to ask the questions in a more general format so that I can establish a solidbase/foundation.  

If you maximize an application that was once minimized and it is not loading, screen is white but the main window maximizes, what are the odds that it is the windows operating system not rending/drawning the window anymore as opposed to the actual application?  Where can I read about how windows handles the events so that I know what happens under the hood sort of speak.  

Thanks for you time and any advice you can offer me.