Sorry, dottedmag. I wasn't wearing my smart cap today.
Basically, hogleg, the file marked "V3-Install" is for older Hanlin V3's with (I believe) 64 mb internal storage. The file marked "V3ext-Install" is for new Hanlin V3's, as well as BeBooks, EZ Readers and so forth, that have 512 mb internal storage. Use one or the other of these files to flash your device, depending on what type of device you have. The file marked "V3all-Live" is for running OI from your SD card and can be used on either type of device. As dottedmag pointed out, the instructions for both flashing your device or running live from the SD card are
on the OpenInkpot site.