you;ll find more than you ever wanted to know here
http://www.robertmcchesney.com/he's written several books on this, including Rich Media, Poor Democracy, which is the one to start with
he also has a radio show every sunday with most excellent guests, ranging from Amy Goodman to John Nichols to Janeane G, to Katrina vdH
well worth a look
from his articles page
The Nader Campaign and the Future of US Left Electoral Politics
The Editors (John Bellamy Foster, Harry Magdoff, Paul M. Sweezy, and Robert W. McChesney), Monthly Review, Vol. 52, No. 9 (February 2001), pp. 1-22.
Journalism, Democracy, ... and Class Struggle
Monthly Review, Vol. 52, No. 6 (November 2000), pp. 1-15. Also available in Norwegian here.
Social Security, the Stock Market, and the Elections
The Editors (John Bellamy Foster, Harry Magdoff, Paul M. Sweezy, and Robert W. McChesney), Monthly Review, Vol. 52, No. 5 (October 2000), pp. 1-13.
Socialism: A Time to Retreat?
The Editors (John Bellamy Foster, Harry Magdoff, Paul M. Sweezy, and Robert W. McChesney), Monthly Review, Vol. 52, No. 4 (September 2000), pp. 1-7.
Introduction: Toward a New Internationalism
The Editors (John Bellamy Foster, Harry Magdoff, Paul M. Sweezy, and Robert W. McChesney), Monthly Review, Vol. 52, No. 3 (July-August 2000), pp. 1-11.
Graham Spry and the Future of Public Broadcasting
Canadian Journal of Communication, Vol. 24, 1999, pp. 25-47.
Noam Chomsky and the Struggle Against Neoliberalism
Monthly Review, Vol. 50, No. 11 (April 1999), pp. 40-47.
Media Politics and the U.S. Left
Monthly Review, Vol. 50, No. 9 (February 1999), pp. 32-41.
The Political Economy of Global Media
Media and Development, Vol. 45, No. 4, 1998, pp. 3-8.
Making Media Democratic
Boston Review, Vol. 23, No. 3-4 (Summer 1998): pp. 4-10, 20.
The Internet and U.S. Communication Policy-making in Historical and Critical Perspective
Journal of Communication, Vol. 46, No. 1 (Winter 1996): pp. 98-124.
The Political Economy of the Mass Media: An Interview with Edward S. Herman
Monthly Review, Vol. 40, No. 8, January 1989. (also here).