Australia is a great spot to live and i am seriously considering moving back.
Some good advice has been given with regards to the temp visa working etc... If you are going for the one year then forget about the tech job and get onto the sites etc.... and enjoy yourself.
I lived with a software programmer and an analyst when i was living in Sydney. Both Irish chaps who had no probs finding work in the tech sector and both were offered sponsorship.
Id say 95% of the jobs in OZ are filled via employment agencies so its those you will have to deal with when it comes to gaining employment.
Have you any formal education in relation to web development ? Web development is one of the jobs where employers dont really care about qualifications but more so about what you can do but when it comes to the sponsorship forms a degree or diploma will help big time.
You could try getting in with a web development company over there but you wages will be low and chances are you wont get sponsored by them unless you are very good.
Try the likes of
SEEK - Australia's no. 1 jobs, employment, career and recruitment site to see what sort of jobs are been advertised.
I worked with a company over in Sydney, once my 3 months was up i was supposed to find a new job in a different sector (temp visa rules) instead the company hired me under a sister company and i stayed for a further 3 months.