The Australian War Memorial :click on the People link at top and choose further to search, e.g. Shirley Gardam, Bangka; Roy Bardenhagen at Morotai.
The National Archive of Australia - a huge repository including entry of refugees who came to Australia because of wars and people interned here during wars.
The NLA Trove millions of newspaper articles, diaries and other documents are scanned and searchable. e.g. Our Soldiers North Eastern Casualties THREE NABOWLA SOLDIERS KILLED IN ACTION North-Eastern Advertiser Friday 2 Nov 1917
Commonwealth War Graves Commission
e.g. J. L. McKenna
Be sure to scroll down for the fill-in form, and on results, much more info, maps, etc (I'm not having much luck with this yet.)
The ADFA A.I.F. Project for WW1 e.g. Wm McKenna of Karoola
World War Two Nominal Roll
e.g. Joseph McKenna
William Henry Watkins
Gravesites of Tasmania
see the fourth button WW Casualties
Thanks to Elaine Hill for lending me her huge folder of collected WW1 and WW2 records. Please contact Heritage Lilydale, we may be able to help with your research.