You might want to take a look at my book: Ultra-Fast ASP.NET (published by Apress). It's oriented at an intermediate to advanced level.
Although my focus is on performance and scalability, I also explain how ASP.NET works from a different perspective than most authors; my goal is to help build a more intuitive understanding of not just how things work, but why they are the way they are, and how the various pieces fit together. There's a high-level summary / write-up and a review on Amazon if you'd like to know more (see the link in my signature).