The second of maybe 3 or 4 videos showing you how to triple-boot your Mac to make it run Snow Leopard, Windows 7, and Ubuntu.
** ALWAYS MAKE BACKUPS OF YOUR FILES BEFOREHAND! **
The second part of the series tells you how to install Windows:
1) Install Windows - Hold ALT/option when turning on your Mac, and put in the installation DVD. Double-click on "Windows", not "EFI Boot". When you get into the installer, go to Custom (Advanced), and click on your partition that you want to install Windows on. Click on Advanced, then Format. Click OK. Click on Next to begin installation. The installer will have to reboot your computer a few times, so if you're not there when your computer restarts, it'll automatically go into Mac OS X, thus wasting time.
2) Install Boot Camp - Boot Camp has all the appropriate drivers for Windows. Just put in your Snow Leopard DVD to install this.
3) Update Boot Camp - You can use Apple Software Update to install the latest version of boot camp. This will make things faster and work properly.
The next video will show you how to install Ubuntu on your Mac. If you'd like, you can do this now. Just put in the burned ISO (to a CD), hold ALT/Option when you turn on your computer, and choose the Windows disc (it will be labeled as Windows).