Expanding research capacity of large research networks within health care delivery systems requires strategically training both embedded and external investigators in necessary skills for this purpose. Researchers new to these settings frequently lack the skills and specialized knowledge conducive to multi-site and multi-disciplinary research set in delivery systems. This report describes the goals and components of the Cancer Research Network (CRN) Scholars Program, a 26-month training program developed to increase the capacity for cancer research conducted within the network's participating sites, its progression from training embedded investigators to a mix of internal and external investigators, and the content evolution of the training program. The CRN Scholars program was launched in 2007 to assist junior investigators from member sites develop independent and sustainable research programs within the CRN. Resulting from CRN's increased emphasis on promoting external collaborations, the 2013 Scholars program began recruiting junior investigators from external institutions committed to conducting delivery system science. Based on involvement of this broader population and feedback from prior Scholar cohorts, the program has honed its focus on specific opportunities and issues encountered in conducting cancer research within health care delivery systems. Efficiency and effectiveness of working within networks is accelerated by strategic and mentored navigation of these networks. Investing in training programs specific to these settings provides the opportunity to improve multi-disciplinary and multi-institutional collaboration, particularly for early-stage investigators. Aspects of the CRN Scholars Program may help inform others considering developing similar programs to expand delivery system research or within large, multi-disciplinary research networks.