Here are a few resources to help you identify possible areas of the Australian economy to examine in your assignment:
CIA World Factbook – Australia (click on Economy dropdown). Up to date statistics and a good overview of the sorts of things you might consider how business impacts upon.
An Introduction to the Australian Economy – excellent report from a respected Australian economist (Saul Eslake). It is a bit old (2007) so don’t use the figures, but use the history or the ideas in it, and find updated figures
Australian Bureau of Statistics – repository of all sorts of statistics about Australia. Have a look around 🙂
Australian Treasury – the government department responsible for monitoring and managing Australia’s finances and economy. Try particularly the ‘Economic Roundup’