TROVE is the National Library of Australia's online database, which includes links to over 500 million different resources.
Google Scholar is a great search engine for finding scholarly literature. It is important that students and professionals source accurate and reliable literature to support claims and ideas. It is particularly useful for essays and reports.
Wikipedia in an online encyclopedia, written collaboratively by the public. Wikipedia is good for finding the basic understanding of an idea or subject. However, it should be noted that Wikipedia is in no way regarded as a reliable research platform to source in an assessment.
ISEEK is a targetted search engine which focuses on information for education. It compiles hundreds of thousands of authoritative resources from university, government, and established noncommercial providers.