This book LOOKS pretty but the contents are superficial, with many factual errors, poor quality maps and half-complete summaries. The author is rather liberal in his interpretation of Tolkien's sources of inspirations and what Tolkien intended when he developed his Middle-Earth. This book is supposed to be about the battles of Tolkien, the who, what, where and battle tactics as stated in the introduction. However, very little of this is evident. There are pretty pictures and timelines, as well as explanations of the historical and mythical background to Tolkien's works, but little about the actual battles. Even the wikipedia page provides more information that the book, but it does not look as pretty.
If you want information about battles and maps, try Atlas of Tolkien's Middle-Earth by Karen Wunn Fonstad and Journeys of Frodo: An Atlas of J.R.R. Tolkien's The Lord of the Rings by Barbara Strachey.
Also interesting is Exploring J.R.R. Tolkien's The Hobbit by Corey Olsen and
Making of Middle-Earth by Christopher A Snyder.