The American Spectator : From a Crotchety Old Man: read all of it, but here are my two favorites:
7) An assertion is not a reasoned argument. Nor is a series of assertions. Your opinion isn't valuable because it's yours; it's valuable if you back it up with reason, with an explanation of cause and effect. And not all opinions are equally valid. And emotion, especially anger, does not an opinion make. And invective isn't a proof of authenticity.
9) There are certain things you must know in order to be a good citizen, among them a basic understanding of American history and civics. If you're in college and don't know the difference between the First Amendment and the First Commandment, you should be ashamed of yourself. If you don't know that the U.S. Civil War was fought in the mid-19th century, or that the Constitution lists Congress as the first branch of the national government, or that the Korean War occurred between World War II and the Vietnam War, then you don't have enough sense to be taken seriously.
Tell it on the mountain!!! [italics added]