First, what this is not:
1. This is not a textbook on eXtreme Programming
2. This is not a textbook on C#
3. This is not a textbook on .NET
This book is, instead, a narrative trip through developing a software project using the techniques of eXtreme Programming, writing in the C# langauage, in an effort to learn the .NET environment.
Ron Jeffries has been a leading advocate of (if not the founder of) the eXtreme Programming concept. Rather than talk more about eXtreme Programming itself (he has several books on eXtreme Programming listed on Amazon) he is using a new format in this book to get away from the heavy tutorial/lecture approach used in the other books.
He, pair programming with Chet Hendrickson some of the time, first goes out and buys some C# text books. The first step is to learn a bit about C# so he starts working on some of the examples -- I was glad to see that the first attempts (like most of my own) didn't work, and he got a not very helpful diagnostic -- this sounds like my learning a new language. Then as he says, "I fumbled around in Visual Studio a fair amount." Yup, I understand. A few dozen pages later, "Well, it almost worked, but it didn't." Been there, done that. Another few dozen pages, "Found a bug, Write a Test. But we don't know how to test that particular bug."
I suspect from this you get the idea about this book. It's got a friendly, chatty, open writing style and along the way passes along some pretty deep messages about the subjects of XP, C# and XP. I like the style, it may or may not be your cup of tea.