The general writing tips in this book are good, but I was a bit disappointed in the amount of tips specific for SF. There are few tips for fantasy, and almost no tips for horror writing. The book does handle basically all aspects of writing thoughs, from the first ideas and how to get them to how to find a publisher, so unless you already own books on writing this book is not a waste of money. I must say that in its further reading and publishing your book sections it is British-centered, but the general ideas there also hold true for America.
If you're a beginning SF writer, this might be the book for you, but if you already own books on creative writing I'd save your money and try to find something else.