This was one of my first dinosaur books as a kid, and I still have it today. It is extremely well written, with lots of detail and information, but still very welcoming to the lay person. The illustrations in the book are wonderful. The book covers a wide range, going over topics like the process of fossilization, to the science and pioneers of paleontology, as well as giving a detailed species account for many different species of dinosaur, most including an excellent color illustration, common and latin name (including pronunciation key), distribution info, and a smaller illustration to demonstrate size/scale. It also covers what is and isn't a dinosaur, to help alleviate the confusion many people have regarding creatures like pterosaurs, etc.
Now obviously this book was written nearly 30 years ago, so there is some information which is outdated, and some of the illustrations, while superbly done, have some outdated representations (i.e., posture, etc). But to rate this book low based on the fact that some of it's info is outdated, is asinine. The book was written nearly 30 years ago, and at it's time was one of the best entry level dinosaur books in publication. And despite it's battle with time and new data, it is STILL an absolutely wonderful book that will not disappoint.