One very useful website for Australian family history researchers is the National Archives of Australia. It holds records that have been collected by Australian Government agencies, mostly since 1901. Not every record is available to view online at this stage, but more are being added all the time. For a fee you can also order copies of the records. Types of records include military service, naturalization, immigration, photographs, patent applications, federal court records, etc.
I have, so far, found five records of particular interest to me. Four for the Beringer family, one for the Wickhams.
Two of the records held for the Beringer family were particularly revealing, giving me family history information I don't think I could have obtained anywhere else. These were statements made by two great uncles, Albert and Charles Beringer. Because they were working in the public service at the time of World War 1, with German surnames, they had to be able to prove that they were not enemies of the state. The records are here and here. Without those I would never have known that their stepmother threw all her stepchildren out of home once they turned 14. That the children all managed to stay in touch without their parents linking them all together is a wonder, but it's lovely to see that they did.
The other two important records for the Beringers were the naturalization papers for my great great grandfather Adam Beringer and my great grandfather Adolf George Beringer. Adam's naturalization papers were where we first found out that he came from Rauenthal in the Rhine Valley, Germany, plus found his exact birth date. Adolf's papers confirmed for us his birthplace of Frankfurt, Germany.
The record of importance for the Wickham family was the military record for my great great uncle Allan Wickham. The record has 55 pages of documentation. The third page shows that he was killed in action in France in May 1917. Often these records contain letters to and from the family if the soldier was killed. Allan Wickham's records are no exception. Pages 25 and 26 of the record have a handwritten letter from Allan's mother, requesting her son's personal effects which seem to have gone missing. She ends the letter with the poignant words "...am sorry to have given you so much trouble, but I should like to get my boy's things." It's not clear from the correspondence whether they did actually turn up. I truly hope they did.