David Willis & Jane Willis 
Doing Task-Based Teaching — Oxford Handbooks for Language Teachers [EPUB ebook] 

Task-based teaching has created enormous interest among teachers in recent years. But how does the idea of designing tasks (e.g. discussions, problems, games) that encourage learners to use real language work in practice? This book explains the basic principles behind task-based learning and teaching and gives practical examples of how to make it work in different teaching situations.