As a manager, you should have a coach when you learn a new skill and you should set the expectation that your team will have coaches when they learn a new skill as well. One key is to use the coach that is best for you and your specific situation.
In Roger Connors' new book - Get a Coach, Be a Coach - he talks about this in detail. One of the best practices that he recommends is that you find a coach who is 1 or 2 "levels" higher than you are, instead of trying to find the top expert. Roger talks about why this is beneficial, but the biggest one to me is that it is a heck of a lot easier to find coaches if you aren't looking for the "best" in a field. Those people are few and far between.
For example, I identified libraries and other non-profits as a great market for me. However, I had never really worked in a library or non-profit, so my knowledge of them was limited. So I found a coach to help me learn the specific things I wanted to know - how libraries train managers, what is the biggest challenge libraries have, and how best to communicate with libraries. I could have found the greatest library administrator in the world and tried to connect. Instead, I found a few people in my local area that work in libraries and I reached out to them. I asked them my questions and they were willing to share their knowledge and experience. It has helped me a great deal.
So when looking for a coach, determine what level you are currently at and find a coach 1 or 2 levels above you. Also, teach your team how to do the same thing.