You need to apply for certain licenses and be a registered company to be able to begin something like that, if however you already have these things thn you will need a fast line, i suggest something like a T3 cable line. This would then be routed into a main server and distributed via whichever way you want (probably via WiFi).
Obviously you encrypt the network and set a hidden SSID so that no-one can acess it without paying you for the information, you would have to change the SSID every day as to not get ripped off by old customers returning and logging in with the same old details.