cisco 2811 Integrated services router configuration

I am trying to configure a 2811 router to allow remote clients to dial in and access mail from Exchange server on LAN.The router has 8 asynchronous lines.The remote client is able to dial in but cannot access any network resources.What steps must i take to ensure connectivity

you must assing a dial pool group of ip which are in a vlan that can access the exchange server. these ip will be assigned to the dial in clients