Welcome to the forum hassan but I doubt that there will be enough repondents or records otherwise available that can easily answer your queries, and the success and time for settling in will vary significantly I imagine with professions and extent to which immigrants have experience sought by employers and also the immigrants flexibility in where they will be prepared to go for work.
There does seem to be a high demand for people in medical and teaching professions and also for engineers in mining and construction, accountants in business and IT people to mention a few. But even with that demand, you will always have people looking to progress their careers, looking at positions that are more challenging and/or rewarding, so you have to perceive that along comes an immigrant and the field of employment may be quite competitive and obviously employers will be looking for employees with best experience that suits the positions to be filled.
And thus your settling in will be affected by how successful you are in attaining work, where it is, and whether you find the location appealing. Then there will be the question of whether you have a family, and if married will your partner want to work or if not, how will she/he assimilate with a new community and quite possibly a very different environment to that used to.
There is a register for skilled immigrants on the immigration site, designed to give you a head start of sorts for it is there for employers to access and see if a suitable employee is going to be available, a bit like putting your CV there and then you could also do the same with various employment agencies/consultants and I would suggest that you have a good read of information on the immigration site that relates to life in Australia.
New immigrants to Australia should not be averse to joining local community groups on arrival and council offices and libraries along with smaller local newspapers, and the internet are all great resources to use in finding clubs and groups that may interest immigrants and doing that will in turn assist in assimilation into the greater community. And then there may be associations of people from your own country and it is natural for some comfort to be gained from being able to mix with people from your home country, but no reason not to do that and also meet with people from other countries, it being reported that Australia has people with links to 200+ countries.
Australia's Culture Portal is typical of sites that can give you some insight into Australia, and the more you can learn of Australia will only assist your settling in.