This chapter discusses record keeping, like maintaining a lab notebook. Historically, lab notebooks were analog, pen-and-paper affairs. With so much work being performed on the computer and with most scientific instruments creating digital data directly, most record-keeping efforts are digital. Therefore, we focus on strategies for establishing and maintaining records of computer-based work. Keeping good records of your work is essential. These records inform your future thoughts as you reflect on the work you have already done, acting as reminders and inspiration. They also provide important details for collaborators, and scientists working in large groups often have predefined standards for group members to use when keeping lab notebooks and the like. Computational work differs from traditional bench science, and this chapter describes practices for good record-keeping habits in the more slippery world of computer work.