With x\p it could not be simpler. Install the network cards in both machines, boot up and install the drivers.
Next connect the cabling between the machines.Switch the machines back on and if you are sharing internet access, connect that machine to the net.
Now on the main \ internet connected machine, run the setup a home or small office network from control panel \ network connections. Follow the wizard through. Make this the main machine.
Do the same with the other machine, through the wizard. It should be up and running in no time.