The chapters in The Handbook of Entrepreneurial Dynamics provide the rationale for questionnaires used in the Panel Study of Entrepreneurial Dynamics (PSED). The PSED is a research program that was initiated to provide systematic, reliable, and generalizable data on important features of the new business creation process. The PSED includes information on the proportion and characteristics of the adult population involved in efforts to start businesses, the activities and characteristics that comprise the nature of the business start-up process, and the proportion and characteristics of those business start-up efforts that actually become new businesses. The handbook also describes the PSED data collection process; provides documentation of the interview schedules, codebooks, data preparation and weighting scheme; as well as offers examples of how analyses of PSED data might be conducted. The authors identify specific measures that can be used to operationalize theory as well as provide evidence from the PSED data sets on these measures’ reliability and validity.