Donquick
You would be best to use something like
192.168.10.x or 192.168.100.x for your work server, which will totally avoid the IP range that home users are likely to use eg 192.168.1.x or 192.168.2.x etc.
As suggested please read the manual linked at top of forums, but the quick answer is to log in as admin and select Configure this server from the Console menu, and then change the server local IP, leave all other settings unchanged. After a reboot, then go around and turn on all the workstations, they should be allocated a new IP in the correct range by the sme DHCP server.