Agreement form to access wireless

Please forgive me if I'm looking in completely the wrong place here,
but what I want to do is setup a wireless server for wireless internet
such that everyone who wants to access it will be redirected to a Terms
of Service page that they must agree to to access the net. Also, I
would like this access to be timed to say 30 minutes before they must
agree a second time (in the end I'm going to switch it to a passkey
system, but this would be easier to start I figured).

Anyway, if anyone could point me in the right direction I would greatly
appreciate it. I'm not opposed to programming, I just don't have any
idea where to start. Thanks in advance!