Several editions have established this book as one of the best companions to astronomy for all levels of interest (including simple naked-eye observing), an introduction to both practical astronomy and the science of astronomy (particularly as it relates to the universe which a backyard amateur sees!). It is based around the monthly star charts, and the more detailed constellation and lunar maps with their accompanying text describing the most interesting objects. The depth of coverage is surprisingly high, so the book is really inexhaustible. It has served me as a permanent companion, even after going on to more detailed atlases and observing handbooks, since no single book matches its convenience and beauty for casual stargazing.
I had an earlier edition of this book, which was an inspiring companion when I was first learning the sky. But I definitely found this new edition worth buying, mainly for the improved star charts - carefully coloured for high contrast between stars and background in both low light and red light. Don't be deceived by the relatively 'washed out' appearance of the background in full daylight. Even then, there is a beauty to these charts that grows on you.
The text is generally just a little improved, with everything honed down and more clear. It is probably for the best that the five-year planetary finder charts are removed to a companion website - not enough years' worth can be included to match the life of the book.