Upgrading From 10.5.8 to Activate my iPhone 5s
So I tried activting my new iPhone 5s which I can only do through my itunes, but I still use iTunes 10. I can't install iTuness 11.1 (which is required for the new iphone) because my operating system is still a 10.5.8. I don't even know where to begin upgrading my OS X. I know I have to purchase the upgrade. But which system to I upgrade to? Thanks!!
MacBook Pro (15-inch Late 2008), Mac OS X (10.5.8)