It is Blog Action Day to discuss volunteering at trials!
I compete almost entirely in NADAC, and most trials are pretty small so everyone really needs to step up and volunteer!
I try to plan my volunteering around times that would be good for my dog to get some crate rest. I usually ask to gate steward, ring crew or leash run. I usually work 2-3 classes per day and then just jump in whenever else they need help.
One thing that seems to really help the small trials is, at pick up time, ask everyone to go out to the field and pick up even one or two items and move them near the trialer to pack up. This really gets things packed up fast and doesn't leave the burden on only a few people.
My JRT is 8 years old now, and is pretty good at being quiet in his crate. When he was just beginning to trial it was hard for me to work, since he barked and got himself really worked up when I wasn't there.
Time and getting used to the trial atmosphere really helped there.
Another great thing volunteering is good for is while you are learning the jobs and watching the rings, you can learn lots of new things and it makes it easier to meet people also!