This book doesn't have anything to add from what i've picked up from internet articles on portraits and also magazine articles. Doesn't have enough detailed information about any lighting/posing that isn't either common sense or gained by reading a couple of websites. My advice is save your money for a better book.
Shorter than the NG Field Guide to Photography but nevertheless packed with useful insight. If you like people and want or need to photograph them, this book will be a really useful guide and inspiration.