I cannot add much to the multitude of great reviews on Amazon.com other than to put my hand up too and say "This book was is one of the best books on writing that I know".
While there are so many vital aspects to writing, I hold plot and structure to be the the most important. There is nothing more frustrating than a book that leaves you with unanswered questions or where the plots don't flow well. When I first started to write, I bought the whole Write Great Fiction series. This title was one of two that ended up so highlighted that it was easier to spot the whitespace that the good bits.
In all seriousness, if you are embarking on a writing career (or hobby) pick up a copy of Plot & Structure and devour it from front to back.
This book's philosophy on plotting is built around James Scott Bell's 'LOCK SYSTEM,' where: L: Lead O: Objective C: Confrontation K: Knockout ending This is aided by clear, and insightful examples from actual novels (for example Dean Koontz, The Door to December) and actual movies (for example Jaws). When done in this way it provides a solid platform on which to structure a novel. Scott Bell explains 3-act structure but rather than talk about 'turning points' he uses his own self-styled 'doorways.' i.e. something has to happen in the plot to push the hero through Doorway Number 1, otherwise the story will stagnate. I found Scott Bell's explanations for these doorways very useful. Again he uses real life examples to make his point. The author breaks novel structure down into beginning, middle and ends and the essential ingredients that each section of your novel needs to work. He also does a nice section on scenes and again offers his own self-styled HIP (hook, intensity, prompt) system to make scenes work. Hook the reader, intensify the scene and prompt further reading. What this book does really well is provide simple, solid platforms/systems around which a writer can build their own story ideas. The style is user-friendly as is the page layout. I enjoyed reading this book and I felt I was in safe hands. It left me feeling confident about developing stronger plots.