Agendas for meetings are nearly as important as the meeting itself.  It will help you stay on track, and with a timed agenda, you can accomplish more in a short amount of time.  When properly structured, the agenda can serve as an outline for the minutes of the meeting to be recorded by the secretary.
The agenda should always include the meeting title or type, the date, time, and location for the meeting.  With a timed agenda you can anticipate the amount of time each topic should consume.  If the discussion continues beyond the time, the issue should be sent to a committee or task force to discuss and return with a recommendation.