I'd propose this:
Cable/ADSL Modem/Router plugs into a large port switch.
You then run one cable per machine and plug into that switch, including Servers and workstations, in a star topology.
Any servers should be plugged into the gig ports, if you have any on the switch.
If you wanted Wireless then buy a modem/router with wireless! If you buy a router with a switch, don't use the switch part...just run a cable from the router to the main switch...giving the switch's interconnected devices Internet access.
Disable the router's DHCP ip allocation...and setup one of the server's a DHCP server.
Make sure you setup a domain controller and assign users that way.
In term's of a patch panel...it really depends on your office layout...but they are usually advisable
Basically you run a cable run your switch into a port on the patch panel...and then the corressponding port at the other end of the patch panel goes into your PC....thus you can move ports around the office floor...but not rewiring the office as you go!
so all the PC's plug into the patch panel and a corresponding cable goes from the patch panel into the switch...and then you have 1 cable coming from the modem into the switch.
1 switch per subnet...get a large one for further expansion, at least a 16 port.
Printers, well if you can get network aware printers, ones with network interface ports...then just plug them into the switch, via the patch panel.
If you have a normal desktop printer...then you'll need to set it up as a local printer on one of the machines and then sharing it to the network.
Software-wise...
in additonal to the nominal Windows 2k3 on the server/s and WinXP on the dekstops...you'll also need...a firewall.
You can either always opt for a hardware firewall to sit in between the moden and the switch...and/or
a software firewall on each machine...and def the server/s. Block everything you don't use
Alos install anti-virus on all machines, including the server/s.