How to localize your app
There's ton of advice out there on the Internet, so we'll try to keep it practical and focus on what questions to ask beyond giving general advice and guidance.
TODO
Think about the architecture first some things are very hard to change later. encoding. db schemas. urls. concept of locale everywhere it needs to be considered (i.e. possibly anywhere -- how to you pass it down? how do you resolve it? what do you ask users? about domains)
Decide what language, region, and locale to support