Hi,
I'm afraid the best documentation we have for how to implement an Editor Provider is the source code itself which has 3 examples, FCKeditor, TinyMCE, and XStandard. So the best bet is to try and learn how these work and then implement something similar for the Telerik editor. Once you code up your provider you need to add it to the list in mojoEditor.config file in the root of the web.
Hope it helps,
Joe