Yep, you're wrong. The "language" is TCP/IP and it is exactly what the Linksys box speaks. The question is whether or not the settings on both Macs are appropriate for them "seeing" each other. In particular, the Sharing Preferences pane is quite important here. If you don't have at least some things selected here, the computer will be invisible to other computers on the same network.
Once you have connected to another computer, you can use "Connect to Server" in Finder to connect to it again-all it takes it checking the box with the "+" before you click on "connect."