As a West Point graduate I feel I received one of the best leadership trainings available to any college-age student. And it is not just leadership that is valuable in the military. It is leadership that is valuable in every day life.
But West Point is not available to everyone for numerous reasons. Yet there's another, some times maligned, leadership school that does an outstanding job: the scouting organizations, in the US the Boy Scouts of America and Girl Scouts of the USA. Both my children went through their programs, one becoming an Eagle Scout (Boy Scouts) and one receiving the Gold Award (Girl Scouts). I did a couple of years in the Dominican Republic Scouts (could not continue due to relocation) and have been actively involved as an adult with both organizations although the majority of the time has been with the Boy Scouts.
I've seen boys grow from ackward, clumsy youth to people who others notice when they walk in; people who take initiative and lead when needed. A great book about what Eagle Scouts have accomplished is Legacy of Honor: The Values and Influence of America's Eagle Scouts. Alvin Townley, the author, set out to travel the USA meeting with Eagle Scouts and getting their stories.
There is a lot we can learn from this great leadership schools. While some of us may be too old to be scouts, we can still join as adults to help (they have training for adults too!) develop young people. And if you don't have time to do that, consider grabbing this book at the library or at your local bookstore or at the link above take a read. It is an outstanding book.