Yes, connection via the router is the way to do it. Have you ever set up a wired network? Do you understand the topography? From the router, you have a wire to the internet or an internet-related device, then a wire to each computer. For a wireless network, the wire to each computer is replaced by wireless. Just like the wired version, where there is NO wire running between the computers, you don't want to try to set up a wireless connection between computers.
What 3Com router do you have, and what is between the router and the wall?
Ah, I suddenly noticed the "I Googled" words, so you can connect to the internet from each computer, right? If that's true, then the network side of things is working, and we just need to get the computers sharing files.
In which case, pick a computer, open "My Computer", right click on the C: drive icon, select "Sharing", and select the options that share the drive. From the other computer, you may be able to select "Network Neighborhood", click on the first computer name, and the hard disk will(*) be visible.
If you're not confident doing this, I can repeat using smaller steps.
(*)Actually, sometimes it doesn't become visible. The easiest way to force it is to reboot each computer, and wait 15 minutes or so. Then have another look.