Mapping Our Anzacs is a great website for researching any ancestors who served in World War One. I find it easier to find people on here than the National Archives website because it is dealing only with WW1.
A page of my grandfather’s records.
William Burnett Willison
I found this information at the Australian Light Horse Studies Centre
2986 Acting Corporal William Burnett WILLISON, a 31 year old Farmer from Parra Hills, South Australia. He enlisted on 6 June 1916; and at the conclusion of the war Returned to Australia, 25 September 1919.
I haven’t looked into the site much yet but there appears to be a lot more information there.