Presiding over a Meeting
If you're presiding, there are a number of things that you will do very quickly, very early on, that will establish the way you want to run the meeting and achieve the order that you desire for your group.
Set the Tone
No one wants a tyrant for a chair. Act like one once and you'll probably be ushered out of presiding very, very quickly. It's important to distinguish firm, authoritative behavior from dictatorship. Entering the room in a confident manner, dressing appropriately, and being prepared will go a long way toward establishing you as an effective leader. The respect you earn by these behaviors and the way you conduct the meeting will eliminate many problems and problem behaviors from people.
Call to Order
As a chair, you should call the meeting to order on time. It's expected that you will be on time, and you should then show your group that you do not wait for latecomers and waste the time of those who have been considerate and have arrived at the expected hour. Doing everything possible to save time without rushing things or appearing dictatorial or nitpicky will also help. Have agendas printed and ready to distribute. Seat those giving reports in the front of the room instead of scattered throughout the group so that the group doesn't have to wait for them to come forward. Be prepared to act or speak in a way that demonstrates courtesy, while insisting, if necessary, that order be maintained and that the participation and contributions of those attending be treated in a businesslike manner.