I just finished taking one of the Berklee free online course through Coursera. It was an Introduction to Music Production Class, and I took it because I was trying to get one of my guitar playing friends to get more into Sonar, so we took it together.
This course was a 6-week subset of one of their regular courses. I thought the instructor was good, but the material was really pretty basic. I certainly would not have been happy if I had spent a lot of money on a course that was constructed at that level, even for an introductory course. We spent a week on essentially how to use a delay.
I think the Power books from Scott give you every bit of bang for the buck, as far as Sonar training, comparatively speaking, but then again, a Berklee collection of courses on Sonar should be seriously in-depth, for the kind of money they charge.
There is a tremendous amount of information on Sonar available, either from books like Scott's, or from the zillions of YouTube videos out there, both free and commercially available. I would think you could find just about everything you would want out there in some form.
Bob Bone