After the first few sections I was neutral about this book. The information about basic matters seemed useful but not revolutionary; the kind of thing that might arguably be better in a magazine article or on someone's blog.
The short section about nutrition contained much that I fundamentally disagree with. Grant Petersen basically argues for a high protein-low carbohydrate diet and even recommends not eating too much fruit or whole-grain cereal. I would have thought that since the book is aimed at ordinary people who aren't just about to do the Tour de France the best advice would be a normal balanced diet. For me this section was out of place, but to be fair things improved hugely from there on.
When discussing the technical aspects of bikes, how and why they are constructed, how to set up the machine to suit you, and so on, the writer is in his element. Contained in these sections is much valuable information that would be difficult to find elsewhere. For me this alone justified the cost of the book and made me forgive what I consider to be some rather dodgy dietary recommendations.
For those who find such things irritating it is worth pointing out that this book is written very much for a North American audience and the style is chatty and informal. Mr Petersen drinks water by the quart and knows the size of his saddle bag in cubic inches. His bike has fenders and he sits on his butt. (However when talking about bike dimensions he works exclusively in metric). This doesn't really detract from the book's value though, as the information and ideas put across are valid anywhere.
All-in-all I am glad I bought this book. It will help you set your bike up correctly, potentially stop you being bamboozled into buying the wrong bike, provide lots of everyday advice and it dispels many of the myths that surround cycling for pleasure.