Alright, I'll maybe be able to answer this:
10.7 related http://www.insanelymac.com/forum/topic/261577-p5n-e-sli-how-to/
Continued
With that being said, because this config worked back in the day there is a strong chance it will work now.
OSx has released 10.9 & 10.10 as a free digital download so unlike prior versions that were 'sold', newer versions of OSx may be posted in case mods are reading this; it is legally fine as long as it is 10.9 & 10.10.
It is best to start with 10.10 and then deal with upgrades as they happen, after you have an understanding of your hardware.
That being said: https://thepiratebay.se/torrent/11232880/OS_X_Yosemite_10.10_%2814A389%29_bootable_USB_for_Intel_PCs
When using this distro, pressing '1' on boot will use Chameleon rather than Clover, this is suggested for someone with no experience.
Chameleon is the 'older' method of installing OSx, as a result it will not have a valid serial number and in 'About Mac' will often be detected as an older model.
When installing OSx, make your main HDD a GUID partition map. don't worry about dual-boot, focus on doing this right then deal with it after freshly if thats the goal.. if dual-booting use MBR.
If you insist on dual-boot use MBR, either way make two (three if MBR) partitions; one in Mac OSx Journaled, Case-Sensitive (OSx is not normally case-sensitive but it makes for better stability and allows for source building if you care)
The second partition should be much smaller, make a FAT partition named 'EFI'
From here, reboot and install windows if you're trying to dual-boot.
If not, go ahead and install OSx.
After installing boot from the USB again and use Chameleon to boot into OSx and then you can install Clover.
http://sourceforge.net/projects/cloverefiboot/
Clover is superior to Chameleon in a lot of ways because it automates generating a legit apple serial, which will allow you to use some Apps and enable iMessages and the iServices.
Install clover onto your FAT (emulated)EFI partition with the following options:
This will enable Clover to be your bootloader and your PC should now be able to boot without USB assistance; but Clover will still not run OS X
My configs for Intel can be found here: https://github.com/Tquet/XPS8300-Yosemite/tree/master/EFI/CLOVER/kexts/10.10
These kext are required for 10.10 under Intel boards, the only thing that is not the same is I have 'Inject ATI' flags specified, in boot options you will need to change this and it can be done easily in Clovers boot menu