[Tiva]

You can't do much, the G4 series was discontinued in 2006 and any updates after 2007 require the new intel core processor for a Mac to get.

Click here to download 10.3.9

For Itunes you can have up to 7.0 but nothing after that will run on Panther.

To update to Leopard(10.5) (that is the last one that G4 supported) you would need to talk to Apple or go online to find it .

Found it Not an official site but it is 20 bucks

Also you can download up to 10.5.8 software update once you get that your Itunes goes up to 10.6.3

Everything has to be done manually though. Your software update button doesn't work anymore for 10.3 and below, support was cut off to them this past June.