We haven't started "officially" studying shawshank, my teacher wants to wait until next year to start course work on it because it is an 18s movie and the age range in the class is 15-18 so not wholly ideal (that, or she recently said she might be going to change the comparative texts we'll be doing to the barbie movie and accompanying novels, but she'll see), but she recommended watching it just to have the film seen before we dissect it piece by agonising piece.
As for what we'll need to do with the film itself, we'll have to study it alongside the drama sive and the novel small things like these. Basically we have to learn quotes and scenes, and link them together in essays and such in the leaving cert exam. And if I remember correctly, we also are studying othello, and those books and shawshank will be related to it as well