Back when the dinosaurs roamed the earth and I was doing my undergrad, there was no such thing as critical thinking course. Critical thinking was something you picked up (or didn't) in a good humanities course. When I got out of undergrad I thought I was pretty clever with my philosophy degree and all but about 7 years later I discovered a new popular movement that was taking critical thinking to a whole. nuva. leval.
Modern skepticism is a relatively new movement that blossomed with the internet. At the heart of modern skepticism is the idea that all claims that are testable should be critically evaluated based on quality of evidence and arguments in their favour. Modern skepticism is not the idea that we can't know anything: Instead it's a philosophy about what are and are not good methods of collecting and evaluating data, and forming and assessing arguments.
Most of my knowledge of critical thinking came from my interest in this movement. One of the best ways to develop your critical thinking is to have it modeled by experts. Here is a list of podcasts, websites and blogs for those of you who are interested in furthering your development in critical thinking beyond the basics. Each resource emphasizes critical thinking a particular area. Maybe start by picking one that's an area of interest for you. One last point is that you should not be turned off by the idea that these resources are about "critical thinking." These resources often present the material in a fun way that's easy to understand. This list is by no means extensive but these are the resources that I've come to rely on.
Podcasts: (on itunes)
Skeptics Guide to the Universe (general science and medicine). This is a good general podcast and is the most popular skeptical podcast. It's informative and entertaining.
Skeptics Guide to the Universe 5x5. This one is a series of 5 minute introductions to topics in modern skepticism and critical thinking.
Skeptoid. Another very popular podcast that is about applying skepticism and critical thinking to urban legends and topics in popular culture. Usually only about 10 min/episode. This is an excellent "gateway drug" for modern skepticism.
Rationally Speaking: Issues in science and popular culture.
Point of Inquiry: Interview podcast with famous scientists and philosophers talking about their recent books. Also talks about the relationship between politics and science.
Reasonable Doubts: Talks about religious claims and current events related to religion.
Quackcast: (a favorite) Winner several years running for best medical podcast. Marc Crislip is a curmudgeon who is a genius and tearing apart bad medical research and claims.
Websites/Blogs:
http://www.sciencebasedmedicine.org/ Excellent resource for checking up wacky health claims. Vital if you to research in this area.
http://www.quackwatch.com/ Database and articles of medical scams and quackery past, present and ongoing.
http://freethoughtblogs.com/ List of tonnes of skeptical blogs on a variety of topics (mostly to do with religion, but not all).
http://www.skeptic.com/ Official webpage for skeptic magazine.
http://theness.com/neurologicablog/ Very popular skeptical blog on a variety of topics.
http://www.factcheck.org/ Mostly political. Good for fact-checking (obviously).
http://www.snopes.com/ You probably know this one, but just in case. Good for checking up on internet memes.
http://www.randi.org/site/ The godfather of the modern skeptical movement: debunking pseudo-science and scam artists.
http://www.factcheck.org/ Are politicians telling the truth? (Hint: Not Often!)
Recommended Summer Reading: (The "Bibles" of Modern Skepticism)
Demon Haunted World by Carl Sagan
The Believing Brain: From Ghosts and Gods to Politics and Conspiracies – How We Construct Beliefs and Reinforce Them as Truths by Michael Shermer
