"Apocalyptic" is a scholarly category that's very interesting. It takes its name from the Revelation of John (apocalypsis is the Greek word for "revelation"), and Revelations has heavily influenced scholarly thinking and writing about this category of books / beliefs / social groups. I don't talk about this stuff much in class because I think we have a better way to approach the same subject -- from the practitioners' side, rather than the after the fact scholarly guesses trying to figure out what the practitioners were thinking about. In other words, I prefer Nephi's "visionary men" to scholars' "apocalyptic conventicles."
But once you're clear on the limitations of scholarship, literature on apocalyptic can be very enlightening. Paul Hanson's The Dawn of Apocalyptic is classic and seminal. Hanson looks for the origin of the people writing literature like Revelations, Daniel, Ezekiel, 1 Enoch, and so on, and he finds it in Lehi's day, among disciples of the prophet Isaiah, whom he even calls "visionaries." Pretty good, for a Gentile.