The World's Prophecy | World News and Forecast is all about them, information, symbols, where they appear, what they once meant and why someone may use them today.
How you interpret them is up to you. I wouldn't trust a Catholic resource with them though. I actually trust very few sources as too much about them is written by them.
Do I find it interesting? Not sure. I never had any interest before, but it becomes undeniable to me that there is a huge impact on American politics and society and the deeper you look, the more you realize that our lives have been designed to go a certain way when there is absolutely no other explanation or human psychology behind doing so on its own.
I suggest watching http://www.theworldsprophecy.com/they-live-1988-movie/ if you have time and then check out some more things about it.
Added: This movie however is the best to get an idea of what we are up against: