Direction to install Ubuntu 12 on Macbook Air hardware. I preferred to dual-boot.

Installing-Ubuntu-on-Macbook-Air

Get the specs for the model MBA. My version was the Mac Book Air 3.1 11". Noted the graphics card so I could load the proper video driver post-installation.

http://www.everymac.com/systems/apple/macbook-air/specs/macbook-air-core-2-duo-1.4-11-late-2010-specs.html

Ubuntu 12.10 (Quantal Quetzal)
http://releases.ubuntu.com/12.10/
64-bit Mac (AMD64) desktop image
http://releases.ubuntu.com/12.10/ubuntu-12.10-desktop-amd64+mac.iso

Since my MBA doesn't have a floppy or cd-rom, I have to install it via USB-stick. I found several pages to install the ubuntu iso onto a usb-stick.

https://help.ubuntu.com/community/Installation/FromImgFiles
https://help.ubuntu.com/community/How%20to%20install%20Ubuntu%20on%20MacBook%20using%20USB%20Stick

Mac OS X

Command Line Interface

    Download the desired .img file
    Open a Terminal (in /Applications/Utilities/)

    Run diskutil list to get the current list of devices
    Insert your flash media

    Run diskutil list again and determine the device node assigned to your flash media (e.g. /dev/disk2)

    Run diskutil unmountDisk /dev/diskN (replace N with the disk number from the last command; in the previous example, N would be 2)

    Execute sudo dd if=/path/to/downloaded.img of=/dev/rdiskN bs=1m (replace /path/to/downloaded.img with the path where the image file is located; for example, ./ubuntu.img, /dev/rdiskN is faster than /dev/diskN). If you see the error dd: Invalid number `1m', you are using GNU dd. Use the same command but replace bs=1m with bs=1M.

    Run diskutil eject /dev/diskN and remove your flash media when the command completes 

A workaround to the-usb-device-is-not-booting-problem is to:

    Install rEFIt.
    Create a bootable start disk using Ubuntu and a USB stick.
    Create a separate partition on the Airs HD.

http://refit.sourceforge.net/
rEFIt 0.14 (6.5M Mac disk image)
http://downloads.sourceforge.net/refit/rEFIt-0.14.dmg?use_mirror=

Install rEFIt; ten reboot to USB-stick.

This will launch Ubuntu in Trial-mode
Use GParted Partition Editor (installed on the USB-drive)
"Command" and search for "GParted" to find the app to run.

Resize the MacBook HD to the size you want for the Mac side
And leave the unused space for the Ubuntu partition

Launch the Install to HardDrive Application; there will we a choice to install Ubuntu "Side by Side" with Mac OS

Follow  install instructions, the reboot without the usb-drive

Select Linux and launch Ubuntu 12.10

Use the "Ubuntu Software Center" application to install "nvidia" drivers.
Run the nvidia application downloaded.
sudo nvidia-xconfig
sudo lshw -c video