Watch this excellent tutorial video:
https://youtu.be/K-z6NxDWfZA
Download android-x86-4.4-RC2.iso (very slow, go out for lunch):http://sourceforge.net/projects/android-x86/files/Release%204.4/android-x86-4.4-RC2.iso/download
Download Oracle VirtualBox for Mac x86
http://download.cnet.com/VirtualBox/3000-2094_4-145711.html