It depends on how you want it to be, on one drive or two?
If two, that will be easier. Just Install Windows on one, OS X on the other and set your bootloader(Clover or Chameleon) a wait time(just a sec). Every time when your computer boot to the bootloader, you can choose partition from the bootloader.
If one, Get OS X 100% working first, I do recommend to manage the partition before installation of OS X. If you already installed OS X, shrink the partition with your OS X installation USB.
Get your bootloader to boot into the Windows installation media, install Windows on the other partition. The rest are the same bootloader thing.
Edited: Your windows installation media MUST be UEFI if you want both OS on one disk because only UEFI Windows support GPT boot disk. UEFI is still recommended if you want it on two different drives.