Building a Leadership Development Program for future board members

I have a vision for providing a one- to two-year on-ramp for prospective board leaders in our organization. While not exclusive to participants under 40, I hope to achieve an equitable balance between experienced retirees and those building careers in a rapidly changing world. I have the financial resources to structure this like (city) Leadership programs and have sketched out content and timelines, but need a thinking partner who understands that I ultimately need a clear value proposition if I'm asking people to devote significant volunteer hours to the organization. In exchange, I can sponsor their participation in our national, Americas, and international conferences, provide facilitator/trainers for limited in-person connection, and asynchronous virtual resources. I know I can't do this alone, and I need help organizing my thoughts before requesting the resources necessary to make this happen.