Free video lectures by Richard Dawkins
A common misconception is that science is a body of knowledge. Science is more accurately described as a process. This misconception is undoubtedly the result of bad textbooks that list known facts like an encyclopedia and tell little about how we come to then and what kind of evidences would be required to challenge them. Most textbooks teach much on what to recall but little on how to think.
I really like Richard Dawkins's prose so I was extremely pleased when he announced that five video lectures were now free to download from his website. I'm impressed by his talent as a lecturer: he leads his argument methodically without getting lost into details, he uses a wide variety of props and samples to illustrate his points, and he interacts efficiently with the audience to keep them alert. Those are the best videos I've ever watched on a computer, be sure to have a look at them.