This is the first paper in a series of five on how to do good quality clinical research. It sets the scene for the four papers that follow. The aims of the series are to: promote reliable clinical research to inform clinical practice; help people new to research to get started (at any stage of their career); create teaching resources for experienced researchers; and help clinicians working in resource-poor settings to conduct research. We set out in this paper the skills clinicians need to run research projects that are relevant to their clinical practice. We focus on how to get the right training in research methodology, choose and refine a good research question, and then how to ensure the methods and data analysis plan are correct for the question being asked.