As we venture into to this exciting book of Revelation, here's some resources I recommend. If you have discovered other good resources, let me know.
Revelation: Four Views: A Parallel Commentary by Steve Gregg. If you only buy one book on Revelation this is it. He does a great job of going through the text, and his greatest contribution is to present the four evangelical positions (historicist, preterist, futurist and idealist).
Dragons, Grasshoppers, & Frogs!: A Pocket Guide To The Book Of Revelation For Teenagers And Newbies! by Jerry L. Parks. This sounds simplistic but actually is a pretty thorough guide and is very Christ-centered.
The Book of Revelation (New International Commentary on the New Testament) by Robert Mounce - good thorough, academic commentary.
The Church and the Tribulation: A Biblical Examination of Posttribulationism by Robert Gundry. This argues that the rapture will happen at the end of the Tribulation. Dr Gundry was one of my professors. To me this is quite convincing.
The Tribulation & the Church by Chuck Smith. If you want the opposite view of Gundry's, Chuck Smith (one of my pastors whom I respect a great deal) wrote this to counter Gundry's view.