Alkacon Software just announced that they are holding open training for OpenCms. At the moment, the five day classes are only being delivered in Cologne but, with sufficient demand, they may be held in other venues.
The curriculum is designed for developers with sections on writing templates and using the OpenCms API. Presumably, end users get an abbreviated customized training on their own implementation.
OpenCms is one of the better documented open source CMS projects and I hear that a book on the new version 7 is in the works. I have not been to an onsite OpenCms training, but the establishment of public training indicates that Alkacon has a repeatable and formal training curriculum.
A partner network and user community exist in the U.S. but not to the same level as Germany and the rest of Europe. A big part of that is that OpenCms development and services primarily revolve around Alkacon Software and Alkacon has not pursued the U.S. market aggressively. Perhaps Alkacon will partner with a few of the U.S. systems integrators to deliver the training as Alfresco has done with Rivet Logic.