http://www.ntop.org/documentation.html
You are asking too much, come back when you have read the documentation. If you have a problem after this we will be very happy to help you and if its a complex problem, go to ntop mailing lists.
Ntop is fairly easy in normal use. Maybe on bridges it need a little configuration but otherwise just install it and run it.
Also you might get more answer if you post your question in the good forum: network.