I was given this book as a present by my parents-out-law, and have read it cover to cover. It's written in an engaging style, and covers some helpful topics for a novice gardener. I particularly liked some of the planting ideas, and the thoughts on making paths.
However, I felt that an experienced gardener would find the book somewhat pedestrian - and that a novice gardener would not find enough detail to give them confidence. The sections dealing with building paths etc are probably stronger than the more horticultural sections. Overall, there wasn't really much sense of how a small garden differed from a large garden, and I felt that narrowing the scope of the book to focus solely on design would probably have been sensible.
If novice gardeners are looking for an idiot guide, I'd strongly recommend Alan Titchmarsh's 'How to be a gardener' - I've found it readable, helpful and well-illustrated.