Connect a PC to another PC to share Internet

Hiya ..
Need some newbee help here.. I have an Win XP PC that i want to connect to another Win Xp PC in another room (10 m apart). One of the PC is connected to the internet via a router. Is it possible to access the internet on the other PC via the first router-connected PC. I cannot connect the second PC to the router since the router is located ina third unaccessable room.
Please list steps to connect and what sort of cable I would require. Cheers !!