How do you find WiFi away from home?

Pretty much any place that its logical to find computers. Restaurants, Libraries, Coffee Shops, Airports, etc.

An alternative would be to get a mobile hotspot, which is pretty much an internet router that you fit in your pocket. You could also use various apps on your Android or IOS Smartphone, turning the phone itself into a mobile hotspot, be warned though this will either skyrocket your bill if you don't use the right apps, or will drain your battery drastically if it isn't plugged in.

Finally, your car. Yep, some of the newer (say 2005 up) Mercedes-Benz, BMW, Chrysler (Jeep, Dodge), and GM and subsidiaries models have built in hotspots that work for quite a considerable distance away from the car.

Coffee shops, fast food and most motels offer free wifi. McDonalds in every city.