Is "clerking" when one follows the judge and fills out the coop cards? Is there more paperwork involved? Do you have to know what you are doing, or will the judge tell you what to write down? Is there such a thing as a "clerk in training?" I would love to do this and I'm great with documentation, but I would be an absolute noob.
Before you clerk, attend shows for a season or so and read your Standard. Certainly read the first 50 pages multiple times, and then start picking individual breed standards to study. Mybe start with the heavy hitters in your region, i.e. the birds that you see the most so that you can take that knowledge to the shows with you and learn to see what you read. Also, it will allow you to understand breeders more fully when they speak.