@Mustapha85,
I just read some of those threads linked to you, it should be really useful for you.
We have alot of immigrants in Australia...Most are here to study, further education as Doctors, or accountancy and whilst they study, they are mainly taxi drivers which is a hard slog here in Australia, 12 hrs shifts 5 days a week, earns around $500 a week, as an average...
The main Cities I believe would be, Adelaide, Sydney & Melbourne.
Depending on lifestyle, Adelaide is like a small Country Town, in it's way of lifestyle... The City to the Beach is 20 minutes away. It is the City of Churches with hills at one end and sea at the other... Less stress I believe.
Melbourne is the City of lifestyle, very funky, loads of great places to dine, interesting old worldy with funky new and the sea creates a river in the middle of the City, alot of trams ... Great place.
Sydney is hard to get around takes an hour to get anywhere, again more lively but you can get lost.
Most choose either Melbourne or Adelaide to start their new life...
Hope that helps somewhat.