With the exception of Norton Internet Security, which I no longer use, this is almost identical to the network I have set up in my home (several more wired computers, but the same internet service and router).  Have you followed the excellent setup instructions that comes with the router?  Have you configured the Norton Firewall to allow local network traffic (essential for sharing the printer).  On any computers running Windows XP, you should disable the Windows firewall if you are going to run Norton Internet Security. 

If you explain where you are having the problem, we can probably be of more help.  Note that anytime you change the device connected to the cable modem, you have to reset the network by turning everything off, then turning on the router first, waiting a few minutes for the modem to synchronize with the network, then turning on the device that is directly connected to the modem, followed by the computers.

Steve

The basic steps are (1) Enable File and Printer Sharing on each computer. (2) Designate drives/folders & printers as shared resources.  And (3), configure all software firewalls to allow local network traffic.  Since how this is done depends on the version(s) of Windows involved and since I don't have an hour to spend writing out step by step instructions, you would best be advised to (1) Look at the help files that reside on your computer, and (2) spend some time at some the following internet sites where you can find step by step instructions.  Then, if  you have specific problems, come back here and ask specific questions:

http://homenethelp.com

http://www.practicallynetworked.com

http://www.helmig.com/

Good luck.  It is much easier that it first appears.

Steve