Trove at the National Library of Australia; http://trove.nla.gov.au/; digitised resources includes books, images, historic newspapers, maps, music, archives.
State Library of South Australia; http://www.slsa.sa.gov.au/site/page.cfm, digitised resources includes books, images, archives and family history research assistance.
Family History South Australia; http://www.familyhistorysa.info/; created by historian Barry Leadbeater in 1996. A very comprehensive resource, relating to the State's early history. Information provided on this site is free, and is multilayered with many links.
State Records of South Australia; http://www.archives.sa.gov.au/; the official custodian for archival records created by State and Local Government agencies within South Australia.
Genealogy SA, https://www.genealogysa.org.au/, is a leading resource for information on South Australian family history. Access to its full digitised database is limited to fee paying members only. Genealogy SA welcomes casual membership to use its resources. This website contains a helpful genealogy template guide for the family history researcher, and many other useful tips.
Other Useful Resources
Australian Dictionary of Biography; http://adb.anu.edu.au/; created by the Centre for Biography, Australian National University. Very informative site, with entries compiled by historians on significant Australians who have contributed to the Nation through their careers. Also created by the Centre for Biography, Obituaries Australia; http://oa.anu.edu.au/, a digitised collection of obituaries published in Australian newspapers.
Bound for South Australia 1836; http://boundforsouthaustralia.com.au/; website dedicated to the State's first pioneers. Packed with historical resources and passenger lists. Worthwhile for anyone researching their early South Australian family history.
Gould Genealogy; http://www.gould.com.au/, Terrific South Australian site, hundreds of free downloads available to assist with history research.
Family Search; https://familysearch.org/search, is the original genealogy website of the Church of Jesus Christ of Latter Day Saints. Information on this site is freely available, but very basic.
Subscription and pay for view family history sites
http://www.ancestry.com.au/, http://www.ancestry.co.uk/, http://www.ancestry.com/, http://www.rootsweb.ancestry.com/;
Popular genealogy websites operated by Utah based Ancestry Information Operations Company. Subscription, or pay for view only.
http://www.findmypast.com.au, http://www.genesreunited.com.au/; websites dedicated to genealogy research throughout the Commonwealth. Operated by UK Company Brightsolid. Subscription and pay