As for the mines and unskilled workers there are opportunities available.
If you have your HR drivers licence then theres always the dumptrucks and such. Otherwise there is usually TA jobs going on construction, and there are definately a few jobs there at the moment with all the large projects.
I myself have just secured work on the Pluto project TA unskilled and i believe its somewhere around the $135k, out on Gorgon the offers for same are $160k or more. Up Hedland way RGP5 is gearing up and they will need the same kind of workers. If you're really keen theres always drilling offsiding. The swings on these jobs are much longer than the equal time a few of the posters mentioned (construcion is generally 4 weeks on 1 off with the option to do longer swings) but you'll find plenty of time to study in the donga at night.
Its hard work but the money is attractive, partly why I have made the decision to step out of my flying job (even though it pays significantly more than any other GA single job Ii've heard and spoken to people about) and into something like this to improve my lot in life and hopefully set myself up a bit for the future.
Good luck with it all.
Wazza