dress business casual
-do think before you speak, nothing wrong with staring at the table for 30 seconds thinking up a logical answer than shouting out something asinine right away
-do emphasize that you are the kind of person who would rather take your time, be safe, and get it right the first time rather than rush and take the risk of screwing up. use that line, and you're golden.
-do show up a bit early
-do say what they want to hear, not what you may do if they give you situational questions
-don't be overly nervous.