Buy a Linksys WRT54G router, it comes with USB ports and you can plug an external hdd enclosure into it and use it as a network attached storage device, also has wireless connections. They are not made any more afaik but you can pick them up less then $100 lots of places 

Thanks, although to be honest, after the trouble I had getting everything to work as it does now, my wife (she runs a home business from her computer) would not all me to to tamper with the Microsoft and Cableone routers we have now.

I was hoping someone could tell me about what settings I need in order to get our home network to let the two computers talk to each other. It must be working to SOME degree now, because the shared internet connection is working just fine.

I'm not really an expert on these things, but I do know that once something is working I don't tamper with it.

they probably are talking to each other. Is there a reason you think otherwise? If they aren't eg you can't 'see' them in network places just right click on My Computer, either desktop or Start Menu. and change the workgroup/domain they listed as