Federal documents such as Birth Certificates and Death Certificates do not need to be notarised before they are apostilled. Other government documents that do not need a notary are:
Certificate of Residency issued by the ATO
Divorce Order printed in colour

Generally if the government document has an official signature or seal it does not need to be notarised.

Many other documents issued by Government departments must be notarised before they can be apostilled.
Documents needing to be notarised include:
Payslips
Article of Association of a Company
Australian Educational Documents

This list will grow as more examples are discovered.