creating a shared internet connection

hi

the present network is a star network with a nt server. (at present isdn is only on the server). i want to create a parrale (cant spell) network which bypasses the server which will connect to a router which will then connect to the isdn connection. is it possible to connect two nics in each machine so they run on both networks?. if so how can you configure the network card to work indipendantly.one is for net surffing and other is for internal use with the server.