No bootable device -- insert boot disk and press any key

It sounds like something happened to your hard drive, or the boot order in your bios may have been changed.

Not really sure what the fix on a Mac would be, but normally you'd check the connections to make sure everything is communicating, and then use a boot/recovery disk to make sure the OS isn't corrupted.

It may be that the disk drive is failing too, so doing a basic check on that isn't a bad idea either.

Your copy of OSX might have become corrupt. To be honest i tried Mac OSX for many years and i find Windows to be easier and less of a hassle... It makes me feel more like I'm using a computer... and not some hipster made OS with issues I can't fix my self without a apple rep every time

also see if there are any mac disk tool cd that are bootable like hirem boot cd for pc. if the drive did not go bad it masy have a damaged file or partion that can be fixed.

You mean you don't like having to run to the Apple store every time your Macbook Pro starts having issues? I thought that was the "in" thing nowadays... you know, not being an intelligent human being and learning how to maintain my own equipment. It's better to pay someone else to do it for me, right?

/sarcasm off

The recovery method depends on what model of Mini you have, recent (Lion or later) include a recovery partition http://support.apple.com/kb/HT4718 if yours doesn't have the recovery partition it should have been shipped with a set of disks.

After a failed bootcamp attemp, I had this. My fix was to hold down shift (I think. Maybe it was the Windows button) for a few seconds. It will ask you where to boot from and delete boot camp partition. That's what I did. I don't really know about your situation