The process depends on the state you intend to work in. I can only comment on South Australia. Here you need to be registered with the Teachers Registration Board. You will be required to send details of your qualifications. Once you are registered you can apply for jobs. If you intend to apply to work in a state school you need to register to teach with DECD. They advertise jobs on there website at certain times of the year. Many jobs advertised are contract positions. To gain permanent teaching positions can take a long time. I was here about 4 years before I gained a permanency. I did relief teaching and got contracts initiailly. DECD has a timetable for advertising permanent and contract positions for teaching and leadership positions. If you gain permanency as a teacher now it is an ongoing position and you can stay at the school as long as you like. Many leadership positions have a tenure period of 3, 5 or 7 years I believe. See attached link for more details.
As you can see the process here is very different to the UK and can be frustrating.
Hope this helps.