As far as it goes, it's fine, but it really doesn't go very far at all, which is a shame. I couldn't believe I got to the end so quickly. As someone else said, you can probably get all this information for nothing with a few simple searches.
Great book; easy to follow, clearly explained, great to read. Especially considering that I'm a younger reader, and unfamiliar with stars as of yet, I found this book very enlightening and knowledgeable, yet not overwhelming.