I recommend this book to whoever wants to learn public speaking. It talks about the most fundamental aspects of public speaking, including ethics, purpose, organization, vocal variety, body language, audience analysis, and etc.
It does not talk about "dry theory" material. Each definition is followed by several vivid examples. It also has very thought provoking exercises after each chapter. Moreover, it provides several sample speeches in the multimedia that comes with the book. Last but not least, readers can go to the website for the book and go through more exercises there.
I find the principles in the book very simple but effective!