My only tip for not acting annoying is don't flake when you get bored. Ask for more work. Run errands for people. If it is okay with them, surf the net. Just don't shoot other interns with those air dusters and staples and get caught by employees. Fun times.
This tip isn't related to your topic, but I think it will be helpful....don't hesitate on doing a task because you're afraid of making mistakes. It's better to make tons of mistakes while you're an intern than on the real job.