To install Ubuntu 12.04 LTF Final Beta is fairly simply as it already comes with EFI support.

1. Just download the ISO from the Ubuntu webpage

2. Write it to an USB disk with command dd or with unetbootin

3. Install rEFIt on your MAC

4. Reboot and select the Linux from the USB key

5. Follow the on screen instructions

6. When prompted to select the partition, click on the EFI and choose “Do not use this partition”, and select the bootloader to be installed in you partition. And thats it. It should suffice for Ubuntu 12.04 Final Beta to boot on your next reboot.

Dont forget to install the fan drivers or your Mac will overheat.

Follow this https://help.ubuntu.com/community/MacBookPro8-2/Oneiric.

Good luck!