Aviation is governed by a series of laws and regulations. It is critically important that you know what these are and how to access them. You will need to make sure that you keep up with changes to legislation and regulation and that you are aware of the issues present in the aviation space that are impacting on the changes to legislation and regulations.
There are many sources of information about the laws and regulations that govern aviation. Of key importance is the Civil Aviation Safety Authority (CASA)
You can find lots of important information on the website, including all the most up-to-date rules and regulations here
Specific information about RPAS can be found here. That site contains relevant information for using drones legally in Australia.
More detailed information, including advisory circulars regarding RPA is available here
The hierarchy of references is:
The Civil Aviation Act
The Civil Aviation Regulations 1988 (CARs)
The Civil Aviation Orders (CAO)
Civil Aviation Publications (CAAPs)
The Civil Aviation Safety Regulations 1998 (CASRs)
Aeronautical Information Publication (AIP) (which contains):
Enroute Supplement Australia (ERSA)
AIP Supplement (SUP)
Notice to Airman (NOTAM)
Aeronautical Information Circular (AIC)
Terminal Area Chart (TAC)
En Route Charts (ERC-H & ERC-L)
Planning Chart Australia (PCA)
You can obtain the relevant CASA information through the website via the links mentioned above.
The Aeronautical Information Publication (AIP) Australia is published on a regular interval by the Aeronautical Information Service (AIS), Airservices Australia.
The users of the drones must make sure they have access to the latest versions of the required documents before they fly.