Not really, just download n' install bootcamp, and get a FULL INSTALL disk of Windows XP. DO NOT under any circumstances use a disk that has been installed and used already, they send codes from your computer and check if its been installed before, you can get a HUGE fine for that.
Btw, you should have atleast 1 GB of memory for any 3D game, the intel GMA950 takes up about 80 MBs of normal RAM to acquire only 64 MBs of VRAM. With only 1 GB it will still run fairly slow. I recomend either Newegg or applesales.com, thats where I ordered a 1 Gig stick so I can get a total of 1.2 Gigs.