The Australian War Memorial should be your starting point for any Australian military research. The AWM holds official records of those who have served in Australia’s armed forces from 1860 (New Zealand’s Wars) to the present day. 

Follow this link for detailed guides regarding what is available at AWM and other repositories such as the National Archives:

Personal service records: Australian service | Australian War Memorial 

The link below provides some general help regarding how to go about researching an individual

Researching a person | Australian War Memorial (awm.gov.au)

The Australian War Memorial also has a library of photographs, diaries and memorabilia for all conflicts and all services. 

There are many photographs taken during conflicts which might show groups in the field, photos of aircraft and crews, memorabilia and diaries.  

You can search on name alone, but it is helpful to have the service number and regiment of your person before you search through the various sections of this site. 

https://www.naa.gov.au/ 

National Archives of Australia holds many digitized copies of military records which will give you a timeline of service for each serviceman or woman.

Records from 1914-1918 are already digitized and work is underway on the 1939-1945 war.

You can also request records of interest and check if there is a fee to digitise for other conflicts. 

It is worthwhile to register online with the NAA and keep a track of your searches and records of interest.