1.Getcha butt to work on time and show up. If you're late for whatever reason, let someone know immediately. And stay after to make up that time.
2.Speaking of which...Be upfront. If something comes up, let someone know immediately. Got a doctor's appointment? Tell your superiors days, even weeks in advance. Illnesses and family emergencies happen, but remember you're at the bottom of the ladder.
3.And unless told otherwise, you don't get time off. Monday through Friday belongs to the internship. Don't plan vacations, bruh. Sorry.
4.Let your supervisor(s) know when you've finished a task/assignment. In busy organizations, your boss might not micromanage you.
5.When you're not busy, still appear to be. Nothing is worse than catching an intern aimlessly on Tumblr.
6.Throw out all preconceived notions about interns that you've gathered from TV and movies. Nobody is getting anybody coffee. This is marketing, not "The Devil Wears Prada."
7.Look like everyone else. Yes, I know, I know, but attempt to blend in your corporate environment. You don't want to draw unnecessary attention to yourself.
8.Say thank you. When you get the position, say thanks. Nothing like a handwritten expression of gratitude, too. When you leave, say thank you. You've gained experience and were under the tutelage of real bosses, regardless of how much you actually learned.
9.But don't assume this will turn into a full-time job though.
Hopefully this helps. You'd think this would be self-explanatory, but you'd be surprised. So enjoy! You're on your way to a real entry-level position!