And now that I figured out that Zone Alarm was preventing the network computers from talking, it started coming back to me... Seems I went through this same burst of stupidity a few years ago when I was setting up a network with cables between the two computers. It has gotten easier with the new computers and new operating systems, despite me.
The setup wizards help, but still require some gnashing of teeth to get working. You have to (at least with XP) have the same workgroup name on each computer, have to remember (WRITE DOWN) the names of everything. Despite the wizard telling me to print down a page of obscure addresses and keys to be entered in each device, this was unnecessary with the wireless router. It all happened automatically.
Once I set up the network (after turning off ZA), I looked (via Windows Explorer) in the My Network Places folder and there were all the shared folders under it. To share a file with other network computers, you need to drag or copy them into a shared folder.
To share a printer after the network is set up: via control panel on the computer the printer is attached to, go to the printer icon and right click on it, then properties, sharing, and click the button to share it. Then on the other network computer, via control panel you add a printer, add a network printer, then browse until the printer shows up. Click on it and add. Then it will automatically add the driver and you can print to it wirelessly, without needing another router.
JohnInKansas, you're amazing.
Thanks you all for your help. If I forget again, someone point me to this thread! (Yes, I did write everything down, but sometimes it doesn't help to read your own notes...) Hope others are helped.