This book is amazingly great from start to finish. All the basics of good agile development are covered clearly and sensibly in the first section: what agile is, how to go about it, why testing and planning are so critical, and where refactoring fits in all of this. Design and general patters are hit in the second section, again in a clear, concise, and sensible fashion -- and with common sense thrown in.
The final two sections cover a real-world case study implementation of a payroll system. Here the rubber meets the asphalt: walking through use cases, building transactions based on smartly-chosen patterns, discussion of what patterns make sense where and why, implementation, packaging, and evolution.
I found myself shaking my head in wonder as I read this book and stumbled across one nugget of gold after another. Some bits of goodness pop out in the middle of nowhere simply because the authors are so well-versed in their domain that they're letting fly wisdom even when discussing other topics. An example of this is in the XP pairing session episode where some discussion of increment operator side effects is tossed in the middle of another discussion stream. You read that section once and pass over it, only to do a head check, bounce back and re-read it while nodding your head and saying "Yeah, that's absolutely right and I might not have caught that otherwise."
Another bit of greatness is the chapter on UML. The authors are emphatic about keeping UML tightly in check and using it only in specific cases where it makes clear sense. Mountains of UML diagrams are not the answer; the authors show where a few concise diagrams make perfect sense.
More goodness can be found throughout the book in the gems relating to any number of design issues such as a small example of a problem the authors put forth to students of their various design/patterns courses: build a coffee maker. The authors go through the most common result they see and show the specific problem areas of that solution -- and then show a solution that is amazing in its simplicity, elegance, and maintainability.
This book is a critical read for folks at any level of experience. I'm going to do my best to make sure it gets on the required reading list for developers at my company.
