We created a Getting Started space where we house documents and videos that are specifically designed for our Community Managers. We have "How To" categories, a list of known bugs, we blog a Tip of the Week, and make Getting Started the go to place for new members and new Community Managers.
When we create a new community, we always customize the space to a particular standard 'look and feel.' Community Managers are free to change that at any time, but it gives them a head start and gets them thinking (and prevents the default space from apearin everywhere).
Helping Community Managers may or may not involve any type of training, but if it does we try to do it in a social way. For large functionality changes, we would usually use a live meeting so that our global CMs could join and/or listen to an archive.
You'll find that people help each other out; often they help each other solve problems before I have a chance to jump in.
Hope that helps (a little!)
We're getting ready to launch a community that has four distinct geographical locations around the world and each will have a community owner. I'm also interested in this.
I'm fortunate that the people designated as the owners will be here for a week and we'll squeeze in a full day of Jive admin training for them. Hopefully that gets them excited. I'm optimistic that the group of people we have chosen will be very active...
One key thing is to look at more around how this helps them and the members get their main job done more than features and functions. Is there a feedback process so that they can forward any suggestions back to you?