LifeWay has multiple short videos on aspects of leadership
See the entire playlist on YouTube or the podcast on Spotify.
https://www.leadershipletters.com/ - writings on Christian leadership and leadership development by Malcolm Webber
5 Distinctives Of Biblical Leadership - Mike Ayers (For The Church)
Beyond Disillusionment: Redefining Leadership In Today's World - Amar D. Peterman (The Inter-faith Observer)
What Makes A Leader Great?: Look For These 5 Biblical Qualities - Steve Yount (Denison Forum)
Stowell, Joseph M., Redefining Leadership: Character-Driven Habits Of Effective Leaders, Zondervan, 2014
Reviews
Redefining Leadership: Character-Driven Habits Of Effective Leaders - Brandon Westgate (Journal of Applied Christian Leadership)
Craig Groeschel Leadership Podcast (YouTube)
Leadership Lessons From The Kings - Bishop Vincent Matthews - 10 lessons, average length 15 minutes
Premium (i.e. paid courses. Often the first lesson is free)
Leadership Basics - Rodney Cooper - 5 lessons, average length 120 minutes
Foundations of Effective Leadership - Sid Buzzell (Our Daily Bread) - 4 lesson, average length 13 minutes
The Four A's Of Leadership For Women - Elizabeth Selzer (Our Daily Bread) - 2 lessons, average length 22 minutes
Ultimate Leadership 1 - Henry Cloud & John Townsend (Our Daily Bread) - 4 lessons, average length 60 minutes
Ultimate Leadership 2 - Henry Cloud & John Townsend (Our Daily Bread) - 5 lessons, average length 60 minutes.
Leading From Your Strengths - John Trent - 2 lessons, average length 15 minutes
(Taught at Bible College of New Zealand, Invercargill Branch, 2004 (now Laidlaw College))
Training resources
Growing The Servant Heart - Free, online course. 10 Modules