As already mentioned, this is not a beginners book, but then again, there are plenty of beginners books on Reason around. What is rare is an intermediate to advanced manual that is, well, actually intermediate to advanced. Kurt Kurasaki has filed the bill with a course that TRULY takes the intermedate user into deep territory.
If you are familiar with Reason, this manual will not be that daunting, and will show you techniques that achieve things that you never thought were possible with Propellerhead's superb software studio. Get through the course, and you will truly have mastered Reason. I found myself repeatedly scratching my head and thinking, "Why didn't I think of that?!"
Now a word about Reason 4.0, and whether the book is useful with the new version. It's out now, and many might ask, "Will this book help me learn Reason even though I have Reason 4.0?" My answer is an unqualified, "Yes!" The book covers all aspects of the program other than the new features, those being the THOR synthesizer, the RPG-8 arppegiator, the groove mixer and the sequencer changes. Virtually all of the techniques learned in the book transfer over to the new modules, as they still use the same back panel elements as previous modules. The techniques I learned in the book have greatly helped me in the use of the Thor synthesizer, as well as the other modules. The exception to this is the groove mixer and sequencer, (in Reason 4.0, they are integrated). Still, this isn't a huge problem, as most of the book deals with module use rather than sequencing, (there are sequencing techniques in the book, but even there, there's a fair amount of carry over, and they translate well to 4.0). Kurt has stated that he is working on a version for Reason 4.0, but if the new book follows previous patterns, it will focus heavily on the new modules while focussing more lightly on the old ones, so it's a good idea to get this book while it's still available, as the 3.0 upgrade was truly a huge one.
Bottomline, if you are an intermediate user looking to become advanced, whether you have 3.0 or 4.0, this is the book for you!