Does iPhone 5 use data when your at home connected to wireless?

Because if you pay family plan 6gb a month do you still get charged even when your connected to wireless? Because I'm so confused right now

No, because you are on Wi-Fi.

Only if it has to. The phones will use Wi-Fi if it can but not if you are making a phone call, a text to somebody w/out an iphone, or a Facetime if you jailbreak back to ios 5.1.1. Not that you can… Yet

No, but you shouldn't even need Wi-Fi if you got a 6 GB data plan.

No you won't be using any data since you're connected to a Wi-Fi signal (your own internet) if you were using the cellular provider's singal (3G/4G/EDGE) you would be charged because it's not your internet connection that you are using.