I am looking for a system I can implement, where a user to my network has to
register the MAC address before access the network. So I am hoping to find
something like this:

User plugs laptop/computer into my wired/wireless network and the go to a
default webpage that I redirect them to. They must enter information about
their system which includes there MAC address. That MAC address then allows
them to access my network. I know some of the big High Speed ISP's are
using this system, and I am trying to research how to implement a smaller
version of that on my network.

Thanks