There is no ‘better’ job board - but there are differences
There are 2 main mediums for job advertising in Australia, the internet and newspapers
The main internet job boards are Australian Jobs, Seek, CareerOne and MyCareer
The main newspapers are the capital city dailies and national dailies
Australian Jobs
A new entrant to the job board market and growing rapidly. Australian Jobs is completely free for advertisers and job seekers and will overtake the traditional pay per ad boards. It’s major advantage is fast Google like searching, rapid job application process and no requirements for wasting time with registrations and so on. You should start your search here for highly targeted and relevant jobs. Check it out at http://www.Australian-Jobs.com.au
Seek
Australias largest job board. Every recruiter in Australia advertises here and many employers do also. It has good search functionality and is reasonably fast.
CareerOne
Owned by News Ltd and reflects the jobs that appear in capital city dailies. Jobs that are on Seek will almost always be here too. The jobs on CareerOne that are not on Seek are generally those that appeared in the press. Basically you should only use CareerOne to track and apply to jobs appearing in the paper. Is powered by the Monster backend and is dreadfully slow and difficult to use.
MyCareer
Ditto re CareerOne except is Fairfax and covers the Australian and Financial Review