Writing SFF proved to be a perfectly good introduction to writing fiction for the true novice. If you're looking for answers to questions such as "how do I tackle the blank page," "what is a protagonist" and "what does worldbuilding mean," this book is a decent place to start. However if you've already read other books on the subject, you might want to give this book a miss.
I was disappointed that only about half the book actually concerned SFF, while the rest dealt with research and editing. Some subjects were glossed over and barely explained - how can you write about Chekhov's Gun without identifying it as such? On the other hand, there were a few new terms and amusing anecdotes that resonated with this Creative Writing graduate, such as the origin of the term Mary Sue.
If you want a quick and relatively cheap introduction to Writing with a capital W, this book won't do you any harm. Similarly, if you want to remind yourself of stuff you've forgotten, it's a good hour's read, but for £3.50 your money might be better spent elsewhere. Nonetheless, this book will be useful to some.