Teaching materials play a crucial role in teaching-learning. When these take the form of a textbook it is essential that the textbook be carefully selected to meet both external requirements and the needs of the teachers. It is also important that teachers be able to mediate between the textbook and the learners, adapting and supplementing the book as necessary. This textbook gives practical advice on the adaptation and supplementation of teaching materials and goes beyond this. For teachers who prefer to prepare their own materials rather than basing their teaching on a book there are suggestions on systematising the process of materials development and on the use of learner-generated materials. The book will be of particular value to practising teachers following a modular Masters course or involved in some other form of professional development, whether organised or self-directed.