the art of the war is indeed a good book. this version though is pretty bad... examples are far fetched and some are either not relevant or too old to be a good reference. I do suggest to get a better version than this. The Art of the War is worthy of your time.
In thirteen short chapters, Sunzi lays out a masterclass in strategy. One sees in Sunzi's work the mark of a Taoist mindset, seeing it in the book's emphasis on engaging in warfare only when necessary, doing things the easy way whenever possible, and never letting one's ego write checks one isn't able to cash in lives.
There is good reason that this is one of the world's most well-known (if not the most well-known) treatise on warfare. Far from being complicated and technical, this guide is full of pithy teachings such as: "War is the way of deception." "No country ever benefited from a long war." "Defeating the enemy without fighting is supreme excellence." "To be undefeated lies in oneself, to be victorious lies in the enemy." "Know the enemy and yourself and victory is assured; know heaven and earth and victory is complete." (And these teachings are even more concise in the original Chinese.)
In addition to basics like leadership, maneuver, and terrain, the book devotes chapters to both the use of fire and spies in warfare. (One's level of understanding is central to strategic victory throughout Sunzi's teachings.)
I'd highly recommend this book for anyone interested in strategy, martial arts, or other strategic pursuits. The book may be ancient, but it's not obsolete by any means.