Technical Help!! Apple IBook!! Software Updates! Itunes! HEELPP!?

Ok. I have an apple ibook g4. I was trying to sync my new ipod touch with itunes and a pop up shows up saying that I needed the 10.2.2 version of itunes in order to sync the device. So I go and download the new itunes and when i try to install it, another pop up shows up saying Couldn't open "Install iTunes.pkg". This package type requires Mac OS X 10.5. IDK what to do. I looked in software updates and it said there was no new updates for my computer. Can someone please help. And PLEASE be specific (directions, links, etc.). THanks