The Making of the Atomic Bomb is an exhaustive history of the development of atomic weapons. It starts with the scientific discovery of the nucleus and moves through the Manhattan project, the dropping of the bombs on Japan to the development of hydrogen bombs.
The book delves into all aspects of the development of nuclear weapons:the science, the politics, the personalities, beliefs, thoughts and motivations of perhaps hundreds of scientists, politicians, soldiers etc.; the numerous difficulties in developing and producing nuclear weapons; the sheer scale of industrial effort needed to produce bombs; the politics of preventing the destruction of humanity through nuclear war, and the weapons projects of Germany, Japan and the Soviet Union.
One thing I particularly loved about this book is how it clarified the myths and other tidbits that I have picked up over the years. For example, scientists clearly knew about the hazards posed by nuclear fallout. Very early on it was known by certain players that nuclear weapons could end up with an arms race, and while attempts were made to stop this, they failed. Germany and the even the Japanese had nuclear programs, but they could never have developed the weapons. These projects and their developments are described in some detail. Especially on the biggest question, dropping the bombs on Hiroshima and Nagasaki, the book is impartial and well considered, and completely well informed.
I would give two warnings on this book. Firstly, while the science is at layman's level, there is a lot of it. I have a scientific background and am familiar with the concepts, but I imagine the sheer volume might be a bit overwhelming for a non-scientist. Secondly the book is very long and very detailed. It's a big, serious read, but you will come away with an intimate knowledge of this incredibly interesting time in history.