Communication is (finally) one of my most important topics at work. Steve Roesler recommends to "add these four thoughts to your leadership communication kit", and I can't emphasize his points enough:

• Never assume that anyone knows anything.
• The larger the group, the more attention needs to be given to communicating.
• When left in the dark, people will fantasize their own reality. Do you want their fantasy to trump your reality?
• Effective leaders are obsessed with accurate, frequent communication.