Best Man:

The best man can be a great help in making the day run smoothly. His main responsibility is to keep people with problems AWAY from the groom. If the kitchen blows up, let the best man deal with it. The groom must have complete confidence in any decision the best man will make and thus the groom can totally relax.

For the best man the fun is in telling the groom all the dramas AFTER he returns from the honeymoon.

Prior to the Wedding:

Plan and coordinate the bachelor party.

Organise the fitting sessions for ushers and groomsmen.

Attend pre-wedding parties.

Attend the wedding rehearsals.

Collect the groom's attire prior to the wedding.

Help the groom with final arrangements, take the pressure off the groom.

The Wedding day:

Make sure the groom gets to the wedding location, on time..

Help the groom get dressed for the wedding, and make sure his personal items are returned afterwards.

Ensure the ushers are prepared and briefed.

Oversee the ceremony seating whilst the groom relaxes.

Pay the churches / celebrants fee after the ceremony.

Sign the marriage certificate as a legal witness.

Make sure the attendants are in their nominated location during the ceremony.

The rings - don't forget the rings!

The Reception:

Be aware of the other guests at the reception, and be the contact for the reception staff.

Toasts are your job. Read the apologies and best wishes to the new couple.

Look after the getaway for the bride and groom. Bags, transport, timing.

Make sure the groom has all necessary tickets, hotel information, traveler's checks, itinerary etc. for the honeymoon.

It's your job to make sure that all men's formal wear is returned to the rental shop following the  wedding. If groom's attire has been purchased you should have it dry cleaned and returned to the grooms house.