Critical thinking is a necessary tool for understanding the world we live in. And I don't believe we teach it particularly well. I know that students in high school science classes learn how to assess the validity/reliability of a source, for example, and that's great, but on top of that we need to get students really thinking about the information and arguments that they'll come across on pretty much a daily basis.
And for that, something like this (found, as is often the case, via Facebook) would be a useful resource:
For example, you'll often see someone advocating for science-based medicine described as a 'shill'. (Apparently all of us on Making Sense of Fluoride are shills. All I can say is, if the cheque's in the mail, it's a long time coming.) This is an ad hominem attack that does nothing to address the person's arguments. In fact, I'd add another: the argument from authority eg Prof X says so, therefore it's true. (We get that a lot.) You'll find some more examples of these rules to work by, here.