Today's new link is on the Revelation page:
UP: Mitchell G. Reddish, “Revelation: Introduction”, Introduction to Revelation (Smyth and Helwys Bible Commentary: Macon, GA: Smyth & Helwys, 2001), reproduced on the Smyth & Helwys website. (PDF)
It's a nice introduction, with side bars and illustrations, an ideal place for the beginner in the study of Revelation.
CORRECTED: Felix Just, S. J.'s websites on Revelation, and Richard Heard's and Robert Grant's chapters on Revelation on the Religion-Online site.