The writers of this book are experienced comedy writers, and I think it's safe to assume that their advice is good. A lot of this information is available elsewhere, for example on the web, and some of it could be considered commonsense. Nevertheless, this information is presented and written well, and it is useful to have it in one place. They do stress the importance of watching and analysing existing sitcoms, which is advice that seems a little obvious. They also emphasise the importance of writing and re-writing, which again seems obvious. It doesn't take long to read the book, and if you follow the advice they have given, actually reading this book can only be the beginning of writing your sitcom.