Router and Network configuration

My company recently split our fractional t-1 line so we could have internet access via a router. I am unable to access the internet though, and believe it has something to do with my network configuration. I have attached the router to a NIC card on the server, and assigned it’s IP address and subnet. The other NIC card is connected to a switch, for our internal network. Using the IP address of the router as the gateway, I am still unable to get a connection to an outside IP address. The internal network has a different subnet than the NIC with the router. Any suggestions would greatly be appreciated.
Eric Morrison
emorrison@flashcom.net