If you have a firewire cable, I would say that the easiest way to get your datas back is to connect your both Ibook together with it and start the broken Ibook on taget mode... Your new Ibook will then mount the hard drive of your old Ibook and you'll see everything you had on it
To start your old Ibook in target mode, just press the "t" key while starting it, your other ibook must already be started though
Good luck