Business agent law are state-based laws - so each state has their own regulations.

In most states, the business agent licences are (stupidly) part of real estate agents licences - so the best place to start of office of fair trading websites in your state.

Also look at Australian Institute of Business Brokers (aibb.org.au)

The ASIC sit is great. Very helpful and to a degree user friendly.

You can also undertake courses. Courses such as a Masters of Applied Finance, or diplomas through FINSIA.