The osx86 forums probably have more details, too. From what I gather, if you buy the right model of PC (including many netbooks), the process has become so streamlined that it's very very easy. You download one app which creates a boot image on a USB stick, boot your PC up with it, then insert an OS X install DVD and watch it go. That's pretty much it.
I don't know what kind of PC you have, but if it's not "exactly" made up of compatible hardware, it might not be worth the hassle. Some machines end up fully functional, others end up ... not so much. I think these people do it just to see if it can be done. "Hey, it works! Sure, there's no sound, the battery life now sucks, the machine can't wake up from sleep, and networking doesn't really work, but it's OS X on my PC!"