The book of Revelation is just so tricky. Everyone interprets it differently, and though there are schools of thought, I haven't seen any that I'm really enamored of. It seems to me that Revelation pretty much interprets itself.
1. The author says it was written to seven churches in ancient Turkey, most of which do not exist today. Thus, it means that the book was supposed to be understood by them. This doesn't mean that they would have seen all the events it expounds, but they would have read the book and said, "I know what that means"
2. The book has over 2000 OT references. So if we understand the OT well and looked at all the references, we might have a pretty good idea of what it meant.
3. The book clearly talks about future events. We just know these events were after the writing, but not when, specifically.
4. The book is a good portion allegorical. Since John often tells us "this symbol has this meaning" like at the end of chapter 1, then we know that a lot of the stranger symbols have specific meanings, which are often explained in either the OT, Jesus or other apocalyptic literature of the time.
5. The ones who are blessed are not just those who read the book and understand it, but who "do" it (1:3). Thus, the book isn't just about prophecies, but about actions that need to be listened to and obeyed. The majority of these commands are in chapters 2 and 3, but not exclusively.
These princples don't explain everything about the book, but I think it explains some. And I think that we can rule out most of the interprtive schools of the book from them:
Preterist: The whole book couldn't have taken place in the first century. Jesus didn't come back. Thus, at least part of the book hasn't been fulfilled yet.
Futurist and Historist: We can't read the book with newspapers (or History books) in our other hand. The seven churches didn't have the benefit of our contemporary literature, thus the contemporary literature must not be necessary for interpreting it.
Thus, I think that the book is full of symbols that could be interpreted in the ancient world about event that might not have occured yet. And one of the main focuses of the book is the life we are to live before God. So even if we get an event wrong, if we get the princples right and live them out, then we are okay.