I think it's safe to say that Steve Garnett's Cognitive Load Theory: A Handbook for Teachers is the book that educators have been waiting for. It is a much-needed, timely resource that puts common sense and cognitive science, rather than hunches and fashions, at the heart of the profession.
There are numerous books which now exist which demonstrate how teachers can take back control and strip away the ineffective nonsense, which of course make liberal reference to cognitive load theory. However, this book, dedicated entirely to the idea that working memory is limited, seeks to delve deeper into this theory. Garnett breaks cognitive load theory down into 14 different effects which impact on a range of stages of students' learning. Each of these are explained, using clear, illustrated examples. Crucially, guidance is given that allows the teacher to consider how to adjust his or her lessons in light of these effects in order to maximise students' understanding and learning.
With input from cognitive load theory's main proponent, John Sweller, this book is a must-read for any educator seeking to improve their practice in line with the most up-to-date research.