ICS does lack usefull documentation, but if you know the behind-the-scenes of what it's doing, it works quite well. I've configured it many times for co-workers to have to travel with their laptops and demo software by allowing customers to share their network connections.

ICS pretty much turns your PC into something like a Linksys Cable/DSL router: enables NAT and a DHCP server and forces your IP address to be 192.168.0.1 (hence dropping off the LAN).