This book, along with "Plot" by Ansen Dibbell and "Description" by Monica Wood are my favorites of the "Elements of Fiction" series by Writer's Digest Books.
Nancy Kress gives a clear and concise guide to keeping your momentum going when beginning a novel or short story. She offers practical advice on most, if not all, areas of fiction writing (e.g. characterization, plots, style). Best of all, she does all of this in an encouraging manner that makes you believe you *can* get through and eventually write the story you've envisioned in your mind.
I find her approach extremely helpful and as a result, I ended up buying her book on "Dynamic Characters" as well. I only wish she could write more fiction technique books!