I set up a gallery for grade school photos. I loaded one photo and a classmate loaded another. They are separate, however, by the name of the poster. Is there a way to combine these so we can group photos, possibly by grade school name?

You could rename your Photo Gallery navigation link Grade School Photos and then create galleries beneath it for each grade school. Photos uploaded to the galleries would still be attributed to whoever uploaded the picture but they would be grouped by school name.