Parts I and II cover the basics on style--how to eliminate clutter, write clear,tight sentences, etc. Part III, the bulk of the work, deals individually with a variety of subjectsthat you might write about--people, places, business, sports, the arts, etc. This is where the bookis most handy, where Zinsser steps out of the writing-guide mold and gives us something unique,something very useful.
Part IV deals much with the process of revision, and talks about thefinal product. This is useful to anyone who has goals of being published. Throughout, this book isfull of humor and wit, as well as a writing style that is very fun to read. The only negative (inmy opinion): Zinsser uses too many of his own pieces as a basis of comparison. Yes, I agree, he ISa good writer. But he's not the ONLY good writer out there. I would have liked to see less of hisown work. The examples he uses from other writers are great--I just wish there were more ofthem.
Overall, this is a must-have for any aspiring writer, or for anyone who likes to write andwants to improve his or her style. This is not the best writing book out there, but you'lldefinitely see an improvement in your style for having read it.