Australian migration

hi shan! Me and my husband along with our 9 mos old daughter, we are planning to migrate in Australia. We will be applying for skilled - sponsored visa, I have an aunt who lives there for 10 years now. She is already a citizen. She and her husband are willing to help us out once we got there. I just don't know where to start. I am actually looking for an immigration agency. But if we can do it on our own I think that would be better for we will be saving money. Please help us.Can you tell us what will be the processes? and the cost of this visa? Thanks a lot!!