You are quite correct a cross over cable between two PCs that both have ethernet ports will work. You will need to configure the network connection on each PC with an IP address (that is different) plug in the cable and ensure that the network configuration (start -> settings -> control panel -> network connections -> properties) includes Client for Microsoft Windows and file and printer sharing is on (if the PCs are running MS )
Click on the TCP/IP properties and set the IP config

I suggest that you use IP addresses of 10.0.0.1 and 10.0.0.2
Set the subnet mask to 255.255.255.0
you will not need to set a default gateway.

Hope this helps

PS you should be able to purchase a cross over cable from most computer type stores (Radio Shack)

Golam