Application Architecture Guide 2.0

Very interesting read.  Discusses everything from development technologies to platforms to design patterns.  Must read for someone new to the Microsoft stack.  Contributions from highly respected Microsoft MVPs.

http://apparchguide.codeplex.com/

Free eBook: ASP.NET MVC 1.0

Not necessarily an entire book but the entire first chapter.  Scott Guthrie and friends have published the first chapter of their new book “ASP.NET MVC 1.0” free for download.

http://weblogs.asp.net/scottgu/archive/2009/03/10/free-asp-net-mvc-ebook-tutorial.aspx