In this video, I install the OpenELEC OS on an HTPC. This starts with burning the disk image to a USB key on OS X, then installing the OS, then setting up the SSH key, and finished off by setting up the second hard drive for bulk media storage.
OpenELEC: http://openelec.tv
The followup video on installing the Emby Server inside of OpenELEC can be found here: • Installing Emby Inside OpenELEC