Communities of practice that occur naturally within an organisation enable the members to learn through participation in practice together (Lave & Wenger, 1991). However, when a community lacks expertise in 21st century practices, learning these skills through shared practice becomes difficult. E-learning is often marketed as if the tools were easy to adopt and adapt, but effective professional development is required to support educators in learning to employ e-learning tools in their practice. Research shows that effective professional development is timely, relevant, flexible, and often collaborative in nature with examples of good practice. The research presented in this thesis describes the design and implementation of professional development which supports a community of practitioners in building the expertise to incorporate e-learning within its professional practice. The research was informed by a comprehensive review of literature on professional development, with a focus on the area of e-learning, the theory behind the communities of practice concept, and the application of that theory. A design-based methodology was employed to gather data from a range of sources of evidence, over two years, in four iterative cycles of collaborative design, implementation, evaluation and redesign. The context in which the research took place was a small educational organisation with an average of twenty staff members over the duration of the study. This staged implementation of an online environment, designed in collaboration with the community, supported the development of a blended community of online practice and provided timely, relevant professional development in e-learning. Analysis of the research findings produced two instruments: (1) a matrix of strategies for enabling and supporting the development of a blended community of online practice, and (2) a heuristic model to guide the investigation of the learning taking place within the online aspect of a blended community of online practice. These instruments are recommended to designers, developers or researchers supporting the development of a blended community of online practice and the professional development taking place in its online environment.