They are the first friendly faces your guests will see at the ceremony, so make sure your ushers know their role
Although not as central as the best man - they don't have to make a speech! - ushers play a very important part welcoming guests, organising the ceremony seating and distributing details of the service.
As friends of the groom, the ushers are obliged to attend his stag night!
Ushers are, in effect, the groom's "troops", helping the best man to keep things running smoothly, marshalling the guests and making sure they know where they're supposed to be.
Ushers should arrive at the ceremony early to greet the first arrivals.
The chief usher escorts the groom's parents and the bride's mother to their seats.
At the church/ceremony venue, ushers help guests find their seats ("Are you with the bride or the groom?") and dispense orders of service, buttonholes, etc, if necessary.
Each usher traditionally accompanies a bridesmaid back down the aisle and out of the church/ceremony venue.
After the service, ushers need to make sure that everyone who needs a lift to the reception has one.
At the reception, ushers mingle with the guests making sure everyone knows where everything is, ie parking, changing, washing facilities.