Once you have organised some teaching, ask the head of the area in which you'll be teaching to complete the online nomination form. You are encouraged to submit each of the forms as soon as possible, and not necessarily together. Registrations of interest will be acknowledged, and you will be informed prior to the beginning of semester whether or not you have been accepted into the Program. You must organise the teaching with a department at the ANU yourself. Typically, the first step in organising that teaching is to contact the administrator of the department you are interested in, who will be able to tell you how to proceed.
Different departments have different methods of organising their part-time teaching.
I have already found that prospective employers are interested in my having done the course. If you're not familiar with the courses and programs offered, try browsing the Undergraduate Handbook . That way you'll have an idea of which courses you might like to teach. Views were freely exchanged, and even when confronting were valuable. The atmosphere of trust created was such that I felt any problem or difficulty could be discussed.