This guide provides a step-by-step introduction to the data management life cycle. It includes examples from citizen science projects and links to best practices and tool to help project organizers optimize the quality, usability, and accessibility of their project data. Many benefits results from following best practices to manage the data life cycle for a citizen science project. Organizers spend less time on data management and more time on project goals by investing in data management plans and practices. Better data management makes data easier to find, use, analyze, share, and reuse. In the long term, following good data management practices means that citizen science data can contribute to decision-making, policies, and research beyond the project´s original scope.