Small office needs help

Due some problems with the economy. I have had to move to a small office. I did this to keep my staff. I have 4 staff working at home. I have an internet connection coming into office. The 4 staff I want to dial in using an ISP, I have a ciscorouter in office w/128 k circuit as well as check point firewall. I want the staff to dial into office for mail (MS Exchange) and, but don’t want them surfing from this connection to the internet.

Any suggestions?