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.

This is the ship William embarked on. The 9th Australian Light Horse Regiment, AIF, 22nd Reinforcement, embarked from Adelaide, South Australia on board HMAT A41 Bakara on 4 November 1916.

I haven’t looked into the site much yet but there appears to be a lot more information there.