Bratcher, "Interpreting the Book of Revelation"
Koester, 1-26 (See Course Documents)
Tashjian, The Second Coming
White, "Understanding the Book of Revelation" (highly recommended)
Apocryphal New Testament Apocalyses
2 Baruch (especially chaps. 53-85)
4 Ezra (especially chaps. 11-16)
Book of Enoch (especially Section II, chaps. 37-71)