There are several very good books out there on the Japanese sword, but in my opinion as a newcomer to this subject, this one is the best. Very straight to the point, lots of information, and many fine black & white photos of Japanese blades in excellent detail.
For me the balance of the book is just about perfect. It tells me in sufficient depth all I want to know about the various aspects of sword making, down to the fitments and the scabbard, and it keeps subject matter like sword appraisal to a nice minimum. I am unlikely to ever want to appraise a sword, in fact it is highly unlikely that I will ever hold a genuine Katana, that being the case, I certainly don't want to be informed of the finer details of appraisal.
All in all a truly excellent introduction to the Japanese sword, and far better than some of the weightier and more expensive tomes that are currently available.