You don't have to be an astronomer to capture the most famous full moon of the year, but it helps to have a calendar. The Harvest Moon is the full moon that appears closest to the autumnal equinox, which falls on or around Sept. 22 each year. The Harvest Moon gets its name because it rises so close to sunset, extending "daylight" for busy farmers.
All rising moons appear larger when they're closest to the horizon. While the moon illusion loses some of its impact on film, the Harvest Moon makes up for it with a dash of color. Because the moonrise overlaps slightly with the sunset, the moon reflects some of the waning purple or pink light with dazzling effect.
To take the best picture of the harvest moon, try to catch it as close as to the horizon as possible and near some visual points of reference, like a barn, a silo or stand of trees. For the best shot, of course, you'll want a nice clear night, but that's more about good luck than good timing.