Passport and VISA for Australia:
Except for New Zealanders, everyone must obtain a visa before travelling to Australia. The type of visa you will need depends on the purpose of your trip and your country of origin (this short questionnaire will help you determine which visa you need).
At any rate, in most cases, all that is required is an electronic visa that does not need to be stamped in your passport. Check this list to see if your passport and nationality qualifies you for an eVisitor visa. If you passport is not on the list, you will have to request a Tourist Visa.
Very often the airline that processes the international ticket requests the visa directly (check with airline). If this is not the case, you can do it yourself at the above links (at least 2 weeks before travelling). In either case, you need to print the confirmation of the issuing of the visa (the airline will send it to you or the government will send it directly to your contact mailing address).
If you have any questions, you can always contact the Australian consulate in your country of origin.