Pretty much all books about the Apollo programme focus on the astronauts, or the important engineers and administrators. Watkins has instead chosen to interview fourteen unknown people who were in some way involved in NASA's project to put a man on the Moon. These include, among others, the NASA chief of photography, a frogman at the Apollo 11 recovery, an instrumentation controller, and the project director for the Lunar Roving Vehicle.
Given that the book is comprised of interviews, it suffers from something of a folksy tone. Also by its nature, the book dwells chiefly on somewhat trivial aspects of Apollo. But then, this is Apollo - and Mercury and Gemini - as these people lived and worked it, and they were not in the centre of the action. In illustration, here's an anecdote from suit technician Joe Schmitt: Buzz Aldrin had been unable to find a right glove for his space suit with which he was happy, and ended up taking a glove from another astronaut's space suit. This glove had to be re-qualified for flight status as it was from a training suit. It's a minor detail, but it provides a simple human touch to an undertaking that to many consists solely of the hardware - the Saturn V, the LM, for example - or the Moonwalkers themselves.
By no means a core work for any collection, it's worth having if you're interested in the human side of the Apollo programme.
Apollo Moon Missions: The Unsung Heroes, Billy Watkins; foreword by Fred Haise (2006, Praeger Publishers, ISBN 0-275-98702-7, 202 pp)