This is a good book. It was my first specialised macro book, and I got it mainly because of the quality of the photos. The book covers a range of topics including lighting, exposure, composition and equipment.
The book is great for inspiration too. As well as providing technical details about the photographs they often provide you with diagrams or photos of the setup used. I find this useful as it gives me ideas of techniques to try .
If you are after a more technical approach, John Shaw's "Close-ups in Nature" is probably a better bet, and in fact it makes an ideal partner to this book.
To conclude, this book is a great introduction to macro photography. It is well written and inspirational - a great buy!