As I edit the videos from my "time management" collection I see that some of them came out better than others. This is one of my favorites.
Episode 27: How to say 'Go Away' to a user and still be polite?
When a user interrupts us with a question and we are busy there are ways to say "go away" without sounding like a jerk. (1) make sure they feel heard. If they don't feel heard, anything you say will sound like a jerk. (2) re-enforce good behavior: teach them the right way to get help (file a ticket, etc.), (3) use the "record - delegate - do" technique for deciding which technique to use.
A little bit of organization (i.e. maintaining a todo list) can go a long way in these situations. Having a written definition of "what is an emergency" can help rebuff people that claim everything is an emergency.
This video has advice about how to handle requests from your boss and how to make yourself look good to your boss, so that you get better raises and promotions.