I have been told that new immigrants to Australia receive a large grant to help them settle in here.
Is this correct?
How much is the grant?

I am an Australian born citizen and I have not heard of any grants for individuals only for community immigration groups etc, the exception being if you have refugee status. The most appropriate site to refer to is www.centrelink.gov.au, this has a full list of payments and grants available and the requirements needed to lodge a claim, there is also a link on this site to access a list of Australian Federal Government Departments including Immigration.