Most charity organisations in Australia have web sites which are the best - and often the only - source of information about that organistaion. You will usually find its history, charitable works, structure and further links to parent bodies etc.
One of the best sites to locate a charity is the AusCharity website which has an alphabetical list of the major charities operating in Australia. use the Search for charities button near the bottom of the page
Another site to search on is the Charities Aid Foundation which also allows you to search for a charity by subject.