Agile Development, in particular, eXtreme Programming (XP), has gained much momentum as effectively to overcome the annoying problem of software development such as mis-understanding of customer requirements, missing deadlines, over-budget, conflicts between customers and developers and poor maintainability legacy systems . However, it is very difficult to teach the skills needed to become agile. In 2002, we, Macau Productivity and Technology Center (CPTTM), began a course in XP and Object Oriented design to teach the skills by hiring a well-known software training and consulting company to do the teaching. While the instructors are very professional and instructive and students happy, they do not acquire the skills taught. Therefore, we decided to develop our own training materials. In particular, we chose 20% of skills in agile development that provides 80% of the value, ignoring the skills are useful but are not other important. Then we explain the essential skills in this example and add a lot of real world examples as exercises. Having adopted a set of materials, students actually acquire the skills taught. In order to share with the community, we held the training material in this book: Essential Skills for Agile Development. (15) Essential skills for communication.