http://www.airah.org.au/
So mad

just typed a really long response and then my system crashed!!!
Anyway - to make it a bit shorter - the OH was army and current trade is mechanic - hates it so wants to retrain. We researched loads and have picked Air con/refrig due to both his preferences and the excellent job opps. Doing it in Oz so he starts off with the Oz quals.
So don't worry love - your OH wont need to go to college as such for a proper course.
He might need to do some registration exams though - I now plumbers/leccies etc all need to be registered to get decent money and that can often entail exams and sometimes even a bit of time at college to get the Oz versions of the quals.
You should find a local TAFE college in the area you want to go and contact them to ask whether he needs to be registered and what exams he might need to take. When we were researching plumbing we did that for one in Melb (can't remember which one - there's loads) and they came back with a list and costs etc. Only thing is - if you email keep at them cos they're pretty rubbish in getting back to you. Above is Air Con website might help x
Hope this helps and if you're off to Melbourne let me know (we can harangue you for jobs when Dan's qualified :D lol).
Good luck x