You should have a lot of volunteering experience or at least know how to do each job in the ring. Remember that seeing that everything is done does not mean doing it yourself.
At check-in make sure you know who your ring crew is. You should be given a list. Introduce yourself to your crew and check that they know their jobs and how to do them.
The 5 jump heights (6, 10, 16, 22, 26) and how to place the bars.
How to set the ascending spread and double jumps, and what to do when going from Regular to Special/Vet and vice versa.
How to adjust the tunnels if they are warped when a fast dog runs through them.
How to check the chute.
How to change the height of the A-frame.
How to change the height of the tire.
The importance of changing equipment quickly. Or as quickly as they can.
Sometimes you do not have the time to train. In this case, pair an experienced person with an inexperienced person. Or work with that person during the event.
Just before the event starts gather the ring crew so that they can prepare for the event.
Make sure the timer is available to start the countdown for walk-through.
Make sure the gatekeeper and scribe get their sheets and check the running order with each other.
Help the timer check the timer poles and program the ETS if necessary.
Make sure everyone knows that no food or drink is allowed in the ring, except water.
Make sure everyone turns off their smart phones during the event.
Assign the ring stewards their seats and obstacles to look after.
During the event be on hand to handle any emergencies. Common ones are timer issues and dogs eliminating in the ring.
Remember that making sure things get done is not the same as doing them yourself. Do not be shy about asking for extra help.