I have a PowerPC G4 Mac OS X 10.4.11 and I need to upgrade to Leopard, but am confused on which DVD install disc to purchase -- 10.5 or 10.5.6? I have 1 GB of RAM and plenty of space on my hard drive, but I know I will need to back up any files just to be safe.
Mac OS X 10.5.6 is just a Leopard update, so you can use the DVD of this version. However, make sure that it's a retail DVD, because you can't use a Leopard DVD that came with another computer to upgrade yours.
Apart from that, the RAM you have should make Leopard work well with your Mac