We have used wiki technology to support large-scale, collaborative writing projects in which the students build reference texts (called WikiTextbooks). The goal of this paper is to prepare readers to adapt this idea for their own courses. We give examples of the implementation of WikiTextbooks in a variety of courses, including lecture and discovery-based courses. We discuss the kinds of challenges that WikiTextbooks address and focus on critical design decisions. Finally, we conclude with a suggested template wiki project that is approachable for new users and appropriate for many course structures.