One thing should be clarified as soon as possible: if you liked 'Moneyball', the movie with Brad Pitt, there are good chances that you might not like 'Moneyball' the book written by Micheal Lewis.
The movie is mostly based on Billy Beane and it is a semi-fictional story of his plan to fight big league baseball teams with just a handful of dollars. The movie is a mandatory viewing even for those that do not like baseball. Directed by Bennet Miller and written by Aaron Sorkin it casts Brad Pitt and Jonah Hill at their best. It should be noted that the character portrayed by Jonah Hill (Peter Brand) does not exist in reality and therefore is not mentioned in the book.
The book is quite different than the movie. Still loosely based on Beane, it's not his story but that of an idea that would revolutionize baseball, economics and other fields. Beane is just the implementer of such idea, or the person that understands that even with a minimal amount of weapons a worthy war can be fought against the most powerful of the enemies.
Lewis' work shows the methods, the battles and the circumstances that allowed a sucky team like the Oakland A's to obtain surprising results. It's a non-conclusive analysis of what developed from the ideas of Bill James' a guy that in his free time started analyzing baseball - and its stats - in order to make it less subjective and more objective.
Reading it was a true pleasure and I confirm that it should be read by any baseball fan. While in some instances it is a bit technical it is never boringly dressed of statistics or math so that even a vaguely interested person might find benefit in reading it. 10 stars!