If you're not an Aussie or a Kiwi, you'll need a visa of some kind. If you're from the UK, you could get a 12 month Working Holiday visa which can be extended to 2 years if you meet certain conditions during your first WHV, but at the end of that time, you will have to leave the country.
http://www.immi.gov.au/visitors/working-…
If 1 or 2 years isn't long enough, you will have to find an employer who is qualified and willing to sponsor you for a 457 temporary visa. For that, you must have qualifications and experience in an occupation on the Skilled Occupations List (SOL). If your occupation isn't listed or if your qualifications and experience are inadequate or unsuited to the nominated position, you have no chance of a skilled work visa. A 457 is the only work visa that can be applied for from a Working Holiday visa.
http://www.immi.gov.au/skilled/skilled-w…