Dual booting Linux with OS X isn't trivial. I've never done it, so take my opinion with a grain of salt, but from what I've skimmed over it takes a little more know-how than dual booting a couple Linux distros, or even a Linux with Windows.
This link should give you an idea of what's involved:
http://lifehacker.com/5934942/how-to...apple-hardware (Linux Mint is close enough to Ubuntu that the instructions shouldn't make much difference.)
Glad to hear the usb keyboard and mouse worked out. Hopefully you were able to pair the Mac bluetooth ones...you just need to go Menu --> Control Center --> Bluetooth, turn on bluetooth if it isn't already, wait (for example) the keyboard to show, double-click on it, and type in the pairing number.
HTH,
Dave