LOL, JP!
Only questions that are dumb are unasked ones, you know that!
Yes, he can connect 2 PC's with just a crossover cable and 2 NIC's.
But if he has more than 2 PC's he will need at least a hub, and then use straight-through cables to patch each PC to the hub.
ICS will work with a number of machines (not sure of the limit - might be 254?

).
BTW, I'd suggest AnalogX Proxy rather than win ICS. More robust, less prone to problems.
Cheers
Mick