Just letting you know that I publicized your website several times during the game project meetings at my university. We've got roughly thirty members, most of which were extremely interested in C# and XNA for game development and found your website the most helpful by far. It's refreshing to see a website that has tutorials focusing on a wide range of XNA content, something that many other websites have not done. Furthermore, your tutorials are focusing on XNA 4 and provide solutions with Visual Studio 2010, which is extremely nice to see considering how many other tutorials are outdated with XNA 3 and Visual Studio 2008. As a fellow game enthusiast and the current president of the gaming project at my university, I have to thank you for taking the vast amount of time needed to build this website and populate it with so many XNA tutorials! It's a real treasure and I'm honestly surprised it isn't the first link returned by search engines (similar to NeHe for OpenGL).
I'm looking forward to hearing more about that book you mentioned, too.