Now in its 10th edition, this introduction to the night sky for beginners has been in print since 1987 and has earned some enthusiastic reviews. The Monthly Sky Guide (MSG) was originally the working title; we never found anything better. It has sold over 100,000 copies.

In many ways MSG continues the tradition of 19th-century guidebooks such as R. A. Proctor’s Half Hours with the Stars. Each month opens with an all-sky chart for mid-evening by Wil Tirion, which is followed by descriptions of the main objects on show and detailed charts of particular constellations of interest. The book is intended for northern-hemisphere users only. 

Information on the visibility of the naked-eye planets for a five-year period is included in each edition; eclipses were added in the fourth edition (along with any transits that may occur). This time-dependent information introduces a degree of obsolescence into the book, although the bulk of the text refers to objects visible each year and so does not date. Full-colour printing was introduced with the sixth edition in 2003; previous editions had been printed in two colours only. The maps have been subtly improved with each edition since. 

The eighth edition, published in autumn 2009, saw the first major change in content since the book first appeared. New sections were added on observing the Moon and the planets, including four pages of realistic Moon maps based on US Geological Survey originals. This expanded the length of the book from 64 to 72 pages. The ninth edition, which appeared at the start of 2013, was the last to be published by Cambridge University Press. The 10th edition, containing planetary and eclipse information for the years 2020–2024, was released in summer 2019 by Dover, the well-known publisher of classic astronomy books. In this Dover edition the number of pages was boosted to 80.

The same printing is sold in the UK, US, and Canada. Various translations of earlier editions have also appeared, although with different edition numbers.