There are numerous web sites which can offer you cheap flights from different airlines: Flight Centre, Webjet, Cheap Flights, the list goes on...
Just make sure that the prices quoted on their sites match up the prices from the web site they have sourced the flights from.
Virgin Blue and Jetstar are two great low fare airlines for domestic flights, Virgin offering great self service check in.
Fancy going somewhere beyond Australia?
We would like to recommend countries such as
Thailand - the people are the friendliest people in the world, there is lots to see and everything is really cheap!
China - it is completely different to life here in Australia and you can get great cds and dvds for next to nothing
Other countries include the usual suspects in Europe such as Italy, France, Spain and Ireland plus countries which are rising in popularity with tourists such as Bulgaria and Estonia.
Lonely Planet is always a good web site to check out for more information on the places to see and what to do when travelling, and for world trips Trailfinders always have great deals