Physics is the science concerned with the elementary constituents of the universe and their interactions, as well as the analysis of systems best understood in terms of these fundamental principles. It attempts to describe the natural world by the application of logic and the scientific method, through a process which includes both modeling by theoreticians and detailed observations and experiments. This book is about how to teach physics effectively. The intended audience is any physics teacher who is interested in learning about recent development in physics educations. In contrast to some other teachers’ guides, it is not a review of specific topics in physics with hints for how to teach them and lists of what common student difficulties are. Rather it is a book with a variety of tools for improving both teaching and learning of physics.