Here's a quick lesson with Saulo about how to control your opponent from the mount from his mount attack series. In this one he covers two different ways to control the mount; the high mount and low mount. Hope this helps and enjoy!
good clip - I would love to see an instructional for holding mount on a big guy though or someone barrel chested when your knees barely touch the ground. They always demonstrate on tiny guys like the one here
Awesome! Basics, basics and basics!
For later 
Saulo has some of the best instructionals in the world. University of JJ consistently has the best old school based BJJ methodologies.