When MVC first came out, I was reading about it everyday and learning all I could about it. About the time MVC 2 RC2 came out, I stopped learning for various reasons (new ho
Microsoft has a good page on ASP.NET MVC 2, which has tutorials covering most important aspects of the framework, as well as several references to blog posts going into things in more detail. That would seem a pretty natural place to start.
For MVC 3 the best resource currently seems to be Scott Gu's introductory blog post.