How to subnet a work station?

I have embled a 16 workstation network with 2 printers and a server. I want to set up the network for TCP/IP. For security reasons, the accounting department (3 workstations) wants to be on their own subnet. I want to create a private (non-routable) network plan which segregates the accounting department. I also want to make DHCP available to visitors, but want each member of the company to have a static IP address. All members of the company must be able to access the server. No one outside of accounting should be able to access any computer in the accounting department. The three accountants want to be able to access files on each others’ systems. so pretty much i need systems’ IP addressing scheme including IP address, subnet mask, and gateway IP addresses for each node on your network. if you can help me i would be much appreciated. so far i got my server subnet(255.255.255.66)and my work stations 1 -16 which wo