Setting up a computer as a router

I haven't had much luck looking through google for this, so I thought I'd ask here.

Due to me not wanting to buy a router/switch, is it tough to set up a computer that is connected directly to my DSL modem, then serves files & internet connection through a second network card to my other computer? Would simply "setting up a home network" share internet connectability?

(I have enough network cards, cables, and a crossover cable)

Thanks.

Windows XP Pro.