Assuming that all you want to do is hook 2 machines together, with no hub/switch and no internet, you need 2 functioning NICs and a crossover cable.
However, since you've made it to the forums here, I assume that you want to share an internet connection between the two. In that case, check out
FiringSquad's excellent set of
guides, specifically the ICS, LAN, and Windows Networking Guides.
I also do not recommend using a crossover cable as it has killed 2 of the 4 NICs I've used it on.