As a supervisor, it is important to set clear expectations. Employees can't do a good job if they don't know what you expect from them or what department goals they should be pursuing.

Make sure each member
of your staff:

has a clear, up-to-date position description

understands your priorities

understands why the work
of your department is
important and what the
department is expected
to achieve

understands what he/she
is to achieve and
why it is important

knows at all times
whether his/her
performance is meeting
your expectations and
why or why not