This record contains the Train-the-Trainer materials for the Introductory Research Data Management Course - Enhancing Longitudinal Data Sharing, delivered by the UK Data Service (UKDS) as part of an initial Population Research UK (PRUK) project. These materials are designed to support trainers in delivering foundational research data management training, specifically focusing on enhancing longitudinal data sharing. The train-the-trainer resources include presentation slides with comprehensive speaker notes to facilitate delivery. These notes provide detailed explanations, context, and practical tips for trainers to effectively convey key concepts and engage participants. The materials are intended to enable trainers to adapt and deliver the course in diverse settings while maintaining consistency with the original design. The course materials have been developed and refined through an iterative feedback approach, informed by the delivery of 10 sessions to diverse audiences. Each session provided valuable insights into the clarity, relevance, and practicality of the content, allowing for continuous improvements. The materials uploaded here represent the final version, optimised to support trainers in their preparation and delivery. The course covers: Foundational concepts in research data management, including the data lifecycle and FAIR principles. Ethical and legal considerations for handling research data, with emphasis on data protection and participant privacy. Best practices for organising, formatting, and documenting data to ensure usability and reusability. Techniques for anonymising data while maintaining research utility. Strategies for sharing data responsibly using responsible repositories and trusted research environments, leveraging licence and access frameworks. This record contains presentation slides for each session, enhanced with detailed speaker notes to assist trainers. These materials are intended for: Trainers and facilitators preparing to deliver the Introductory Research Data Management Course. Institutions or organisations looking to adopt and implement the course as part of their capacity-building efforts. These materials were created under the Skills Development for Managing Longitudinal Data for Sharing project, funded by the Economic and Social Research Council (ESRC) and the Medical Research Council (MRC). They are intended for individuals seeking to improve their research data management practices and for trainers delivering similar content.