All in all, Daniel Marston does a fine job in summarizing this conflict. Most students in America learn about the French & Indian War. Few students realize that this war was really just one theater of operations in the larger Seven Years War. In this book, Marston provides a good overview of this other war. This is no small feat as the war encompassed four major theaters and lasted for nearly a decade.
As with all Osprey books, the chapters are broken down into the familiar sections of background, fighting, chronology, and the various portraits of civilians and soldiers. "The fighting" chapter is first broken down by year. Within each year, the author further breaks down the fighting by geographic theater, North America, Western Europe, Central Europe, and the Indian subcontinent. Clear geographic maps are located in the early part of the book. As the reader goes through each year, they are taken to three different continents. Remembering where a certain battle took place in relation to a previous engagement can be confusing. By referencing these geographic maps, the reader is able to keep up with the author. Of course, the fact that the reader even needs to keep up with the author is a bit of a negative.
Clear maps that show the disposition and movement of the opposing forces accompany some battles. For example, the maps of the Battle of Minden and the First Battle of the Plains of Abraham are in color and provide excellent detail. Unfortunately, the author used antique maps to support other battles. The maps of the Battles of Kunersdorf and Zorndorf are practically worthless from an information point of view. They are a nice addition as a form of art but provide no useful data on the battle itself. In some cases, the reader is unable to even see the map's legend.
The chapter on "The World Around War" provides fascinating information on the economic aspects of this conflict. Mr. Marston does an excellent job of illustrating how each country financed its war effort and the ramifications of those decisions. Finally, the author leaves the reader with a few gems in the last chapter. Most people learn that a major cause of the American Revolution was the issue of taxation. Here, the author shows how the seeds of discontent were sown well before taxation became an issue. He briefly mentions the Quebec Act of 1774 which gave certain rights to French Canadians based on their catholic religion. England also gave them administrative rights over the new lands in the Ohio Valley; a move that incensed the thirteen colonies.
Bottom Line: This book is a pretty good summary of what was clearly a world war. Some of the maps are weak and the constant change between theaters of operations can be confusing. Nevertheless, Mr. Marston should be given credit for covering such an expansive war as well as he does. All things considered, the book is well worth the time spent reading it.
That is only fair seeing how the bookmark will be on someone else's book the next go round. Hopefully, we won't run into that too much. Sometimes, it can't be avoided.
I will check his biography out. I have a lot of books in line already. 
