You were on the right track with iiNet and AARNet. "Mirror" means that the company iiNet keeps a copy of the installer so that people can download it. There are lots of mirrors so that people can choose one that is close to them geographically for a faster download. You could pick just about any mirror you want, but picking an Australian one like AARNet or iiNet will give you the fastest download.
Unfortunately, since internet in Australia is shithouse anyway, downloading big files doesn't always work on the first try. It would probably work better on your second attempt.
Primary mirrors are kept up to date more often than secondary mirrors, but you could pick any of them and get the same result.
Thanks, you'd think they'd make it clearer and simpler for newbies installing these systems, like me for example...but I'll try it again on my old netbook, which still has windows xp, and see how it goes.
Here's the user guide for Linux Mint, Cinnamon Edition:
http://www.linuxmint.com/documentation/user-guide/Cinnamon/english_17.0.pdf
Or Google "How to install Linux Mint" as there are several other guides out there for people with various levels of experience.
