I'm after exactly the same manual, 'ibk01.pdf'. It's not available from the link that mark2 gave, nor it seems anywhere else on the 'net. Spent a few hours looking yesterday.
From what I've read on forums and newsgroups, it seems that Apple are very secretive about service manuals and are happy to take legal action against sites that do host or post them. As soon as someone openly posts a link, it soon disappears... I've found the manual for the Dual USB iBook ('ibk_dusb.pdf') though.
They are available from Apple's global exchange server, but you need to apply for access and be an Apple 'service provider'. I think it's a shame, personally, that they are so secretive when it comes to service manuals - but then it's all about the mystique that is Apple...