One of the fundamental problems with capitalism as it is currently practiced in many countries around the world is that it relies on continual growth. Obviously, this is not sustainable. The Center for the Advancement of Steady State Economy (CASSE) is an organization that seeks to explore the true costs of growth-based economics, as well as considering alternatives. Their website is full of readings, and they also have a collection of videos, slideshows and audio recordings. There is even a humor section.
If I were doing a unit on business or the economy, I would absolutely use materials from this site. Many of the readings are fairly short, and the language is pretty down to earth.