its easier to do this on the Vista pc if you are new to it cuz its more simple.
just open up Windows Explorer and click on Network. If you are in the same workgroup, both PCs should show up in there.
but generally speaking, if you havent messed with any settings and just plugged in an extra LAN cable, it should automatically put you into the same workgroup/network.
as for setting up the games. not too sure about wolfenstein and farcry, but for the CoD games other than MW2, it was simply a matter of going into LAN games, having one person host the game and the other join... dont even need to use console commands unless you were planning on playing on non-standard maps.