I'm not quite sure how you have it set up. It *sounds* as though your husband's PC is connected to a router, he's enabled Internet Connection Sharing on the router connection and you have connected *directly* to his PC by crossover cable. You should in fact have your PC connected to the router as well.
If the router is not a "wireless" one, then to connect a Wi-Fi enabled laptop to the network, you need to plug a "Wireless Access Point" into one of the router's LAN ports, which effectively makes it a "Wirelesss Router". The laptop would then connect to the rest of the network, and the Internet, via the Wireless Access Point.