Let me save you some time and effort. This won't work. The iBooks used either the G3 or G4 CPU, which will not run Windows directly. So your project is already doomed to fail before it's even begun. Only MacBooks and MacBook Pros have the Intel chips needed to do this.
The only way to get Windows onto an iBook is via some kind of virtual machine software to act as a translator, and it will be slow. You'll be lucky if apps run at 80% of native speed.
I have an old iBook that I just want to completely wipe clean and install windows XP on (I know...blaspheme). Before people start questioning why I would do such a thing...it's only because I need the laptop for DJing in which I have an external sound card that only works with Windows. The main problem is that the CD drive doesn't work so I am uncertain how to go about erasing my hard drive and installing XP via USB.