Here's an excerpt from Burns' Civil War series which demonstrates the effect:
One thing this clip demonstrates is how judiciously zooms and pans are added. The point is that just because you can add motion to a still image, it doesn't mean you should. As Burns describes in this Pointer Online article, "What we seek is meaning, and any movement, however dazzling or frenetic, if it doesn’t have meaning, it doesn't have a place."
Pointer Online touts itself as "everything you need to be a better journalist". The site includes plenty of useful articles on reporting, writing and photojournalism. You can learn more about Ken Burns' work at the PBS web site.