President Barack Obama and GOP nominee Mitt Romney will spar over foreign policy in their final debate on Monday at 9 p.m. ET at Lynn University in Boca Raton, Florida. To prepare yourself for what's in store, check out our viewer's guide, or read about the most important issues both candidates will have to address. While some say that Romney will have trouble holding his own on the foreign-policy front, it's possible that lower expectations will work to his benefit. Either way, the internet is likely to be abuzz as the last showdown unfolds.