I've recently been on a binge of reading books about media consolidation, the process of journalism, news critiques, etc. One book I'm really loving is Don't Believe It!: How Lies Become News (New York: Disinformation, 2005) by Alexandra Kitty. Here is the Disinformation page on it and here is the Amazon page with editorial reviews.

I've read plenty of books about the rightward swing of the press and the whole influence of the press by right-wing talking points and such. This is one of the best I've read. What sets Don't Believe It! apart from other books of this type is a more neutral approach to detecting bias and false reporting. Instead of just detailing particular instances or the general structure of "The Republican Noise Machine" (David Brock's book), she analyzes the particulars of the journalist's craft, the points where it is prone to manipulation, and the weaknesses of the current state of mass media in general.

If you want to become a savvy consumer of news, this is the book to read.