How much will it be for me to start a plan with AT&T?

I used to be on my mom's plan with an iphone4, but she decided she was going to stop paying the bill. This is like the 5th time she has done this, and I'm tired of it, so I want to start my own plan. I already have the iphone, so I don't have to buy a phone, but I will need to pay for the data plan, and I want unlimited texting and I want plenty of calling minutes with unlimited nights and weekends.

How much will it be to start up the new line, and how much will I have to pay monthly?

At&t has a new share plan with unlimited text and talk plus share data call at&t and find out more. Hope this helps.