This book has a respectable pedigree, being the result of collaboration between the Natural History Museum and the Open University (OU). Although it's a set book on the OU's short science course on Darwinism, it's not a text book: "99% Ape" is aimed firmly at people without any special scientific background.
Most of the book is made up of a broad survey of the contemporary science of evolution, although there are references back to Darwin's original work. As well as the obvious biological aspects, including human origins, there are also chapters on topics such as evolutionary psychology (fascinating) and the evolutionary roots of altruism ("why be good?"). The science is topped and tailed with a bit of the historical background to Darwin's ideas and a short chapter on science and religion.
"99% Ape" is well written, well produced and illustrated with excellent photographs and diagrams. The writers are all OU scientists who are specialists in their fields, but with the knack of communicating scientific ideas clearly to a general readership.
The only fly in the ointment is that the scientists also wrote the small amount of non-scientific material. The OU has specialists in the History of Science, Sociology and Religion: they should have been used. Historians might also have introduced some balance to the over-the-top hero worship ("Darwin cannot be criticised") and the absence of material about misuses of evolutionary ideas (the "science" of eugenics is glossed over in a few sentences). For this reason, "99% Ape" doesn't get the 100% that it might otherwise have merited.
Even so, an intelligent and intelligible introduction to this fascinating and important topic - just as long as you stick to the science.