Since Windows 8 is not supported by Bootcamp (http://support.apple.com/kb/HT1899) the best option is to use a virtual machine like Parallels, Fusion, or VirtualBox in order to install Windows 8.
What is the best way to add Windows OS to an MBP and MBA? I have heard of bootcamp and a software called Parallels (?) but I am not familiar with either. I also read online that bootcamp does not support Windows 8 currently. Thanks!