Windows OEM on Mac

I need to load a copy of windows on my imac to run boot camp for my son to play some games that are too new for my PC. Can I use the Windows disc that came with my PC to do this>

That is likely a violation of your end user license agreement, especially if the relevant PC is still in use. At a minimum, if XP, it needs to be a single disc with SP2 on it. And more than that, it may not work - you should search the forum because my recollection is that some manufacturer-specific Windows discs will not work in a Boot Camp installation, but some may. You can buy a new Windows XP SP2 generic OEM disc online relatively inexpensively - and it will save you lots of time over the situation that would occur if you have a mucked up install under Boot Camp.

Good luck