I'm assuming you're MAME'ing the cabs.
The biggest thing for noobs to keep in mind is that arcade monitors are very commonly LOW RESOLUTION (less than 640x480, for the most part). To interface your PC to an Arcade monitor you'll have to go one of two routes usually.
ArcadeVGA - Buy whichever card matches your motherboard, either AGP or PCI-e. From there it's usually plug n play. These cards are iffy with x64 OSes, from my understanding.
-OR-
Soft-15KHz - Hit or miss if it will work with your video card. Most Radeon 9200 or higher cards seem to work well, and most nVidia cards newer than Series 4 (i've got am on-board geforce 400 series running it) should work, with updated forceware (offhand i believe it's forceware 66.71).
After that, it's a matter of wiring Red to Red, Green to Green, Blue to Blue, a Ground, and a Sync.
Pinouts.ru Is a good place to find your VGA pinouts.