These are videos, podcasts, articles and books that, I think, provide the basic knowledge for skepticism. These are the essential tools that every active skeptic should have.
For those who don't have a lot of time to go through this whole post, here's a mini guide for Critical Thinking 101.
*Scams, Sasquatch, and the Supernatural by Brian Brushwood
This is a great lecture by magician Brian Brushwood. It covers a lot of the basic topics of skepticism and it's fun to watch.
*Dr. Eugenie Scott: Science and Skepticism
How are science and skepticism related? Is skepticism a part of science, or is science a tool of skepticism? Dr. Eugenie C. Scott, Executive Director of the National Center for Science Education, discusses these questions, and explores the importance of teaching both science and skepticism.
*Introduction to James Randi
I think every skeptic should know who James Randi is. You should visit his website and read his book Flim-Flam! His organization, The James Randi Educational Foundation (JREF), offers a $1 million challenge to anyone who can prove psychic powers or anything supernatural or occult. It's been offered for over 40 years and no one has claimed it.
*James Randi's fiery take-down of psychic fraud
Legendary skeptic James Randi takes a fatal dose of homeopathic sleeping pills onstage, kicking off a searing 18-minute indictment of irrational beliefs. He throws out a challenge to the world's psychics: Prove what you do is real, and I'll give you a million dollars. (No takers yet.)
*The Enemies of Reason: Slaves to Superstition
*The Enemies of Reason: The Irrational Health Service
This is the two part series entitled "The Enemies of Reason". Richard Dawkins points out some of science's achievements and makes the case that it "frees most of us from superstition". The basic topics of pseudoscience are covered thoroughly in this documentary. Part 1 is "Slaves to Superstition" and Part 2 is "The Irrational Health Service". Excellent Documentary. I have also included extended interviews with Derren Brown and Professor Michael Baum.
A look at some of the principles of critical thinking.
A look at some of the flawed thinking that prompts people who believe in certain non-scientific concepts to advise others who don't to be more open-minded.
*It Could Just Be Coincidence
A poor understanding of probability leads many people to put forward supernatural explanation for events that are far more common than they think. This video shows how probability theory is sufficient to explain even seemingly remarkable coincidences.
*Arguing With Ghosts
A brief look at the pointless exercise of telling people, rather than asking them, what they believe.
*An Introduction to Skeptical Activism by Dr. Steve Novella
This is a great lecture by Dr. Steven Novella. Dr. Novella, from the Skeptic's Guide to the Universe podcast and president of the New England Skeptical Society, gives a lot of insight into skeptical activism and the basic things that every active skeptic should know. This lecture was hosted by the New York City Skeptics.
-Skepticism 101 by The Skeptics Guide 5X5 podcast
*The Scientific Method
*The Ideomotor Effect
*Extraordinary Claims Require Extraordinary Evidence
*Logical Fallacies: Straw Man Argument
*Correlation and Causation
*Argument From Authority
*Argument From Ignorance
*Poisoning the Well
*Moving the Goalpost
*How to Argue
*Slippery Slop/Post Hoc
The Skeptics Guide 5X5 podcast is five minutes with five skeptics. They discuss a single topic for five minutes and the panel consists of the cast from the Skeptic's Guide to the Universe podcast. Including: Dr. Steve Novella and Rebecca Watson from the Skepchick blog.
This excellent Wikipedia article lays out the basic characteristics of scientific skepticism and skepticism in general.
*A Field Guide to Critical Thinking
James Lett from Skeptical Inquirer offers an excellent guide on how to think critically and scientifically about the world.
*Scientific Skepticism, CSICOP, and the Local Groups
Scientific skepticism defines skepticism around the principles of scientific investigation. Specifically, scientific skepticism addresses testable claims; untestable claims are simply outside the realm of science.
This brief guide by psychology professor Ray Hyman, a member of the CSICOP Executive Council from the beginning, has for many years been used by Skeptical Inquirer’s editorial staff and widely distributed to authors and others.
*Critical Thinking: What Is It Good for? (In Fact, What Is It?)
Nearly everyone is in favor of critical thinking. This is evidence that the term is in danger of becoming meaningless. Skeptics should spearhead the effort to clarify what critical thinking is-and what it is not. The stakes are high.
*Teaching Pigs to Sing: An Experiment in Bringing Critical Thinking to the Masses
A skeptic encounters psychics, astrologers, and other strange creatures and discovers firsthand how they react to science and reason. Included: a fable about testing the Tooth Fairy.
*How To Argue
A great article on how to argue effectively by Steve Novella.
*Playing by the Rules
It is useless for skeptics to argue with someone who doesn’t play by the rules of science and reason. If no amount of evidence will change your opponent’s mind, you are wasting your breath.
*The Basics: Critical Thinking, Informal Logic, The Scientific Method
Mark Roberts has put together a complete package of links including Carl Sagan's Baloney Detection Kit and a simple guide to common logical fallacies. These links will provide you with just about all the basic knowledge you'll need for Critical Thinking 101.
*Critical Thinking by Robert T. Carroll
The author of The Skeptic's Dictionary put together this topical index for critical thinking. Very useful resources here.
*Logic & Perception by Robert T. Carroll
The author of the Skeptic's Dictionary has provided a lot of information on logic and perception. Always good to have working knowledge of these concepts. If you go to the root for claims of ESP, Psychics, Ghosts or any other weird thing, you will find that the explanations are often psychological or illogical. This link provides you with a wealth of information.
*The Fallacy Files
The most definitive website you will find for teaching and examining logical fallacies. Each fallacy on this website is thoroughly explained with examples. The website's Taxonomy of Logical Fallacies is quite useful.
*Top 20 Logical Fallacies
The rag-tag team of skeptics that make The Skeptic's Guide to the Universe podcast give you the top 20 most commonly used logical fallacies.
*How to Win Informal Arguments and Debates
The title says it all. The basics on how to make effective arguments in debates.
*Propaganda and Debating Techniques
Orange-Papers.org gives you some great propaganda and debating techniques.
*The Demon-Haunted World: Science as a Candle in the Dark by Carl Sagan
This book should be required reading in every high school and college. This is the most popular and most recommended book in the skeptical community. It's easy to read, covers the basics of skepticism thoroughly, and chapter 12 is Carl Sagan's famous "Baloney Detection Kit". A must read for all skeptics and all people.
*Flim-Flam! Psychics, ESP, Unicorns, and Other Delusions by James Randi
The classic work of the master investigator of psychics and scam artists that includes his many personal investigations within the world of the paranormal. A must read!
*How to Think About Weird Things: Critical Thinking for a New Age by Theodore Schick, Jr. & Lewis Vaughn 6th Edition
This text shows people how to assess the most perplexing and ingrained beliefs about the paranormal, supernatural, and mysterious. Its central premise is that well-founded beliefs of any kind require good reasons, that sorting good reasons from bad is possible (even in the realm of the mysterious), and that learning this skill is both useful and empowering. How to Think About Weird Things demonstrates step-by-step how to apply principles of critical thinking to countless extraordinary claims, and shows why the principles themselves are valid.
*A Complete Book List
This is a COMPLETE book list of the best skeptical books you can find.
This should provide you with all the tools you need to fight the good fight against pseudoscience, superstition, and all other forms of non-thinking.