My buddy over at Think Atheist posted a link to a quiz on religion from the U.S. Religious Knowledge Survey. It's pretty fun to test your knowledge and see how you measure up against the rest of America. Jews and Atheists/Agnostics scored the highest. Interestingly the questions vary from legal to comparative religion; you'd have to be very familiar with lots of different cultures, literary history and Supreme Court laws on religion to get them ...
If you're interested in religious mythology, astrological symbolism, or supernatural folklore, grab my book Gods of Myth and Man. You can go buy it on Amazon.