I'm planning to use this book myself! Some of the exercises are directed toward younger writers, but hey, I can live with that.
I wish I had had this book when I was a teen. I wanted to write, but there really wasn't anyone around for guidance. This book breaks down the writing process into doable sections, with a call for Writing Time and an exercise at the end of the chapters. The suggestions require some reflection, not just routine situations. One of my particular favorites asks the budding author to construct the conversation of a brother and sister plopped down on an unfamiliar street corner.
Teens--and others--who are interested in writing should enjoy this book.