I just built my first Hackintosh. I took an old G3 case and modified it to accept a new motherboard. I used an intel DG41 motherboard with a Core 2 duo processor. 4 GB of RAM, 250 GB SATA HD, Nvidia Geforce 8600 video card. Bought all of my parts on newegg.
Found the OS X installation very easy. I used iBoot and Multibeast. Mostly followed this guide:
http://tonymacx86.blogspot.com/
Basically, you burn a boot CD, boot from it, then stick in your Snow Leopard DVD, and install. It installs to your HD, then you reboot off of your boot CD again, select your HD, it boots up OS X, then you run the MultiBeast, it makes your hard drive bootable, and has options to add kexts for your hardware.
I even installed 10.6.3.
All of my hardware is working. No hours spent trawling the internet, no time wasted messing with configurations. They system is stable right now, have been using it for a couple of days without problem.
The hardest part of the process was trying to get everything to fit properly in the G3 case!
So, this was a pretty easy process to do as far as the actual installation. I find the guide on the tonymacx86 site to be excellent, and the install and configuration couldn't be easier. Wasn't much harder than installing on a normal Mac.
Just my two cents for anyone wanting to give this a try.
Before purchasing, I made sure that all of the hardware I was looking at would work well with OS X. For that, OSx86 wiki has a good database, or just google the part and OS X.
It's fun! It's easy! And, I only spent about $450 total on my parts, shipping, everything.