Oh this book is a classic.
I went through two translations - the first one also was too full of historical things that few people care about.
But essentially the book is a collection of sayings and theories of Sun Tzu about military strategy.
The strategies and things that he says are actually wide applicable in life, business, sport, etc.
I read it a couple of years ago, but it made a big impression on me - I still remember a few saying here and there by heart...