Windows 2000 server VPN

I have a Windows 2000 Server and would like to setup a VPN so that two of our employees can access a Act database from home. The office is running a DSL Cisco 675 router and both users also have DSL at home. This is my first configuration in setting a VPN Server and Client up. Can anyone give me good examples in how to do this? I was also told that I would have to configure the DSL router at the office.