http://www.samurai.com/5rings/
Musashi writes about the various aspects of Kendo in such a way that it is possible for the beginner to study at beginner's level, and for Kendo masters to study the same words on a higher level.
This applies not just to military strategy, but to any situation where plans and tactics are used.
Japanese businessmen have used Go Rin No Sho as a guide for business practice, making sales campaigns like military operations, using the same energetic methods.
In the same way that Musashi seems to have been a horribly cruel man, yet was following logically an honest ideal, so successful business sems to most people to be without conscience.
Musashi also (on the evidence of the translations I've read) was a very bad writer. He rambles. He belabours small points and elides greater ones. He is repetitious, but his repetitions are without variety so rather than reinforce his points, he dilutes them with boredom. In fact, the book reads to me a lot like marketing blurb. Specifically, like the "white papers" that software tool vendors give away: there's only enough detail about the solution to make the potential customer realise just how very hard the problem is, so they'd better buy the tool/training/whatever. --KB
I'm not sure it is even possible to describe martial art training in book form. Those repetitions are the essence of martial artistry and, in the Chinese and Japanese traditions, the way to the (lower-case t) tao of the art. But putting that onto paper makes for boring reading. --NatPryce