Greetings,
In choosing books to purchase for a home library, I would say that it is important to take a balanced approach. A good budo library should contain a number of different types of books. These can be technical, psychological, biological, historical, and anecdotal (biographies). When looking at books about martial arts history, take a good look at the bibliography. If the list are short or reference only other martial arts books I would advise against it.Always take a good look at the qualifications of the author. Are they an acknowledeged expert in their field? Do they speak and or read the native language of the art they are writing about? Would their book stand up to academic scrutiny?
If you want to know about the history of a country that is the birthplace of your art, go to the History section of your local bookstore, not the martial arts section.
Read books about combat stress written by pyschologist, not martial artist.Books about zen written by experts on Zen (BTW I've heard it reported {NPR} that there are more books written about zen in the library of congress than any other single topic, seems there is a lot to say about nothingness).
Check out the International Hopological Society web site for an extensive reading list, I won't try to recreate it here. It is one of the best list I have seen, and I've spent the last four years using it as a buying guide and I have not been disappointed yet. I would also recommend the reading list compliled by Meik Skoss on the Koryu books web site.
I hope this is helpful.
Best regards,
Bruce Mitchell