The Australian Securities and Investment Commission (ASIC) website provides useful information and a range of helpful calculators.
http://www.fido.asic.gov.au/fido/fido.nsf

and the Australian Government Understanding Money site has some helpful budgeting advice and tools.

http://www.understandingmoney.gov.au/Content/

*Please note the above links are provided for information only and does not constitute general or specific advice. Before making any investment decision, you need to consider (with or without the assistance of a financial planner) whether this information is appropriate to your needs, objectives and circumstances.