I bought this book as I needed a detailed, proven, reputable and cheap trianing programme to get me through my first Ironman triathlon later this year. The book itself is written in a very accessible, easy to understand way. The first half explains the justification behind the 6 month training programme, which is presented as a day-by-day programme in the latter half of the book. It is reassuring to know exactly what needs to be done and when, though for any newbies to Ironman, don't launch yourself straight into the programme - spend a few weeks building fitness or you will risk injury and burnout afer a month of following the programme (I speak from experience!)
That said, I am following this programme and have noticed improvements in my fitness, so it does work. The only downside is that the swim distances are written in yards, and learning some of the shorthand for swim and cycle drills takes a while. But once you are familiar with this side to the training programme you are fine. I would recommend this book to anybody who is doing an Iron distance triathlon or interested in entering an event.