I've written some instructions on dual booting Android and Ubuntu-from-USB on the MINIX Neo Z64A ... see here

I've also created a USB image for Ubuntu 14.10 (Utopic Unicorn) that was prepared by running the installation steps and it can be downloaded from here and once uncompressed, written to a USB using either “Rufus” (in Windows) or “dd” (in Linux) and booted directly from the BIOS ... see the instructions for further details.