All too often a parent will buy the "blue light special" telescope for their children, yet the child is quickly frustrated with inferior optics, a wobbly stand, and no knowledge of what to look at and why. This book will allow those parents to grasp the basics of astronomy and therefore teach their children to appreciate the universe. Mr. Dickinson has presented material so that everyone can enjoy the night sky; whether viewed with a telescope, binoculars, or the naked eye.
For those older children or adults, this book will allow them to jump headfirst into astronomy as a lifelong enjoyment. If you want to have only a basic understanding of the celestial bodies, this book is more than enough. But in the last few pages, Mr. Dickinson tells you where to go to find greater resources to further knowledge. Because of his recommendations and my own research, I've acquired the following items that I would also like to recommend:
Sky Atlas 2000.0 by Wil Tirion (a great resource for finding objects not usually in the astronomy magazines' monthly inserts)
The Backyard Astronomer's Guide by Terence Dickinson (this is a "sequel" to Nightwatch and between these two books, they are used about 80% of the time compared to my other resources)
Turn Left at Orion by Guy Consolmagno (I enjoy using this book to plan an observation session for "old favorites" or as a "highlights tour" for showing to those new to astronomy)
Other resourses that are more in depth that you may want to consider if you become very serious about astronomy:
Burnham's Celestial Handbook, Volumes 1, 2, & 3
Deep-Sky Companions : The Messier Objects
A subscription to Sky & Telescope or Astronomy
I can't say enough about Nightwatch. This may be your first, or your "first and last" book on astronomy. But either way, you will enjoy astronomy because of Terence Dickinson's writing.
Perhaps, the most useful aspect of the book is its available in spiral bind. It makes so easy to navigate the pages and keep it spread around during observation.
The second useful aspect, especially for the beginners, is the charts of constellations. I own the SkyAtlas 2000.0, but the info in it is sometimes overwhelming. But Nightwatch displays the brighest objects of deepsky in easy charts and also gives quick info (light years, magnitude, is it good for binocs etc) right below the object. When my friends visit my back-yard, this book is helpful in locating the star and also give them quick funda about it.
In fact just binocs and this book are enough to spend a dark sky night. This book along with Backyard Astronomers (by same author) will probably be a complete beginners library. (Backyard Astronomers gives more details about telescopes).