One of the cornerstones of my management philosophy is:
Without the ability to communicate well, a manager is doomed to failure, no matter how well he or she does in every other required area.
How should you communicate?
Lindsey Pollack, writing at abcnews.com, suggests that how you communicate information is predicated on the person you're communicating to. [By the way, she's right!]
That means you must understand your boss (or your subordinate) well enough to be able to make that correct decision.