First, follow [link|https://www.ifixit.com/Info/ID-your-Mac|this|new_window=true] nifty little tool to figure out what type of iBook you have. When you reach the end, it will show you what computer you have. Click it and it will take you to your computer's page. See if there is a guide for screen replacement. Hopefully (fingers crossed) there is. However, if there isn't a guide, you'll have to find one on the internet. If you have to do that, you might as well [guide|102668|create a guide|new_window=true] so others won't have to dig around to find help on replacing their screen.
Good luck!