Come now gents... he/she is just asking a question, no need to crush their dreams... yet.
Shady, your question is a bit broad. You want to be an Internet Service Provider, though there are different levels of ISP out there. Your room mate could be an ISP, and providing internet to his house mates. I provide services to a small private community, and would be called the ISP for those people. Or are you trying to setup your own Internet Cafe, Hotel access point, or wireless setup for a community/town/district?
A lot of the wireless guys use MikroTik hardware and that can also give the ability to create users with caps, etc.
If you are starting small, and are doing the internet cafe or hotel thing, or even for a dormitory, etc, then try software like Partonsoft's Firstspot or Antamedia Hotspot.
Anything bigger than that, then you should be able to find it on the web as I know I have in the past. Though don't expect to pay only a few thousand rands for it. Otherwise, as koeks said, develope your own.
