Providing and using technical assistance for capacity building within educational agencies is a complex endeavor. The U.S. Department of Education funds technical assistance centers to support state education agencies (SEAs) and local education agencies (LEAs) in the capacity-building process. Established in 2018, the Center to Improve Social and Emotional Learning and School Safety (CISELSS) was charged with providing support to and building the capacity of SEAs and LEAs to implement social and emotional learning and school safety--related policies, programs, and practices. In this report, the authors review the literature on organizational and individual capacities and develop a conceptual framework that ties these capacities with common aspects of technical assistance provision. Using this framework, they describe how CISELSS designed and implemented its technical assistance, as well as the technical assistance recipients' existing, desired, and built organizational and individual capacities and capacity-building experiences. The analyses presented in this report reveal important insights and implications for technical assistance providers. [For a related report, "Seeking Balance in the Provision of Technical Assistance: Insights from the National Center to Improve Social and Emotional Learning and School Safety. Research Report. RR-A1161-1," see ED616025.]