I've used yearbooks to pin down activities like clubs and nicknames as you mention, but they can also give you data as to when the schools opened or closed, changed names, etc. It's also cool to see the photos of the school grounds and building interiors from the time period, especially if you could never get there to see the present building(s) for yourself. My grandfather and two great-aunts were all public school teachers, but I didn't know when one of the three had started working. I could confirm it using the yearbooks. Believe it or not, the copy I found online had my great-aunt's signature in it! (It's a thing in the States to get as many people to sign your book as possible before school lets out, or at least to get your favorite people to sign it.)
Ancestry has some yearbooks, but I suggest checking with the school(s) directly if you know the facility's name. The first place I look is usually off the library link on the website, often as part of the school archives. Many, many colleges and universities have already scanned their yearbooks here in the U.S. If you don't see any or don't see the year you're looking for, email the archivist, reference librarian, or whoever seems appropriate from the website.