Much emphasis has been placed on network individualism and the power of the Internet to support independent learning through a multitude of learning resources, opportunities and relationships. This chapter examines how an online learning community can support teachers’ continuous professional development within a social network. The Community of Inquiry framework is used to investigate: the development of teachers’ competence in online collaboration, how social aspects contribute to learning and how online tutors influence the development of critical thinking and meta-cognition. This action research study was undertaken within the European Community’s e-Twinning initiative, where Learning Events are short duration, non-formal learning opportunities for teachers. The participants teach a range of subjects at primary and secondary school level in general and vocational education. The research suggests that teachers need to have the opportunity to apply what they have learned in practice and to reflect on that practice with peers in order to develop knowledge-in-practice. As a result they gain belief in the value of the changes being applied and develop knowledge-of-practice that is seen as essential for long-term change. The research also highlights the essential role of the tutor in designing activities that engender collaboration, encourage critical thinking and foster mutual support amongst peers. Finally, the research emphasises that social presence is essential for effective collaboration and that sufficient time, space and activities should be included in online learning communities. The research has implications for Community of Inquiry theory and future Learning Events. An emerging model may be useful for designing and moderating future online learning communities for continuous professional development of teachers, and other professional groups.