Because of its subject matter, both the teacher and the students will likely end up making a lot of references to classical mythology and Christian doctrine and art. Edith Hamilton's Greek Mythology may prove to be a useful resource for the former, and the Bible will almost certainly be a helpful resource for the latter.
Students may also have some familiarity with works of classical literature like The Aeneid and The Odyssey, which Milton references and partially models his book upon. The teacher can also attempt to scaffold off of students' previous experiences with English literature, such as with Spenser, Shakespeare, and Dryden.