Yes, I took a class that had a lot to do with this recently. Have a question prepared to ask at the end (have several, just in case it's answered during the interview), and do some research about the company, so when they say "What do you know about our company?" you can actually say something. Dr. Unne has it right.

Don't fold your arms. You'll look like an ass. Shake the interviewer's hand. If it's done panel style, always answer the question towards whoever asked it. They will probably ask you to tell them a little about yourself. I haven't checked your age, but if you've graduated high school or college, don't tell them when. Naming the school is fine, but don't give a date. BE ON TIME! Yes, that's a big one. Punctuality is a huge plus for employers, so be on time. In fact, throw that into the "Tell us about yourself" response. Speak clearly. Don't mumble. Dress well, nothing too flashy, no piercings that aren't in your ear, not too much makeup, no makeup at all if you're male. I know there's more...