Executive Sponsorship is so important, but organizations do it many different ways. What I find is that choosing the right sponsor, and being clear on what they do is critical. So how does your organization find sponsors at the process level and for the organization? And what critical value do they add?
There is a white paper by Lombardi on the BPM Institute site
How to Scale Your Process Documentation Initiative
that has some good ideas, but at a more sophisticated level. I go more simply with clients to start.