Gridskipper's Beginner's Guide to Frankfurt
Gridskipper's Beginner's Guide to Frankfurt is a great quick read if you're planning a short trip to the city: "It's no Berlin or Munich, but this fine sausage-making metropolis still has a few delights to offer. Most of the city was obliterated during World War II, so much of the usual euro-touring is replaced by cruising the streets, noshing sausages, stopping in countless apple-wine bars, and hanging out with opera fiends. If that's your thing, we have a few choice recommendations for your maiden Frankfurtage."
I spent my whole life disliking mustard until the first time I tried it on a street sausage in Frankfurt, and then my eyes were opened to its wonders! If your only exposure to sausages is hotdogs from street carts or at the ballpark, frankfurters in the city they're named for will blow you away as they exist on a different plane of tastiness altogether.