If you are interested in the history of the Soviet space program, this is THE book, along with its continuation, "the Soviet space race with Apollo". Everything you wanted to know about mankind's first effort to reach outer space is in here. It's full of thousands of previously unknown facts and stories, covering everything from the first pioneers to the efforts in the late 70's. However, be aware that this is not a book for the beginner or as a casual reading. If you're not familiar with the subject, it may be too exhaustive. On the other hand, if you are looking for blueprints or engineering details about Soviet rockets and spacecrafts, look elsewhere (NPO Energia's book, full of pictures, is the perfect companion).
The only thing I didn't like were the (few) small black and white pictures and diagrams. Although interesting, such a book deserves better. Also, the small typeset makes the reading a difficult task.
The ultimate book on the early Soviet space program.