<<< I come from the time when cars had starting handles >>>
It's a while since I've used one of those, but I've started a diesel generator set very recently by "cranking" it with a handle! :-)
I've edited my standard "blurb" on wired networking to try to keep it as jargon-free as possible:
To create a wired network for Internet access and File/Printer sharing, you have essentially two options-
1) Install a Network Adapter in each PC (if not already installed) and connect them directly with a crossover ethernet cable. “Internet Connection Sharing” is then enabled on the actual Internet connection (the modem connection) in the “host” PC and the “client” PC will have Internet access provided the “host” is running and online.
When you enable “Internet Connection Sharing” on the Internet connection in the “host” PC, it automatically configures the Network Adapter with the correct settings (actually an IP address of 192.168.0.1 and subnet mask 255.255.255.0, but you shouldn't need to get involved with this unless there are problems). The “client” PC’s Network Adapter should be set to get its IP address automatically from the “host” PC.
If you run the Zone Alarm firewall in your “host” PC, the Internet Zone Security level must be reduced from High to Medium or “ICS” traffic will be blocked.
2) The preferred option for connecting more than one computer is to use a broadband Router and, with ADSL, this should be a combined “Router/ADSL Modem”. This replaces the USB modem which cannot be used with a router. All networked computers connect directly to the router with ‘straight-wired’ ethernet cables.
With a router, it is the router which connects directly to the ISP and not one of the connected PCs. The router in turn allocates the IP addresses to the PCs, using one of the address ranges reserved for Local Area Networks, usually 192.168.xxx.xxx
Either of these options will additionally allow you to run File and/or Printer Sharing across the network.