After you have downloaded the OS X Mountain Lion installer, launch LionDiskMaker
and it will locate the installer app, extract the disk image, and then make the boot disk. It’s about as simple as it gets.
For burning a boot DVD you will need a 4.7GB or larger blank DVD and a SuperDrive. For USB install drives or SD cards the drive needs at least 8GB of space available. LionDiskMaker formats the drive you point it at, remember that when you are picking a disk to make bootable for the installer.