Hi lynzi,
We moved to melb last june and our gal is 16mths now. It is different, having to cope without family support or helpers but we (and alot of other families like us) managed... Some of us are SAHM, or work part-time while their kiddos are in part time childcare. There are also full-time working moms with kids in fulltime childcare. Childcare can be ex but there are some rebates depending on household incomes.
It may be tough at first, trying to settle for a place to stay and find jobs, and find a social network and make friends but it is possible. I have made friends in melb through forums like these and on FB. People have been generally helpful and nice towards "greenhorns" like myself. Life is alot slower than back in SG where both hub and i were holding full time jobs. Now we have plenty of time for our gal and we are loving it.
Perhaps you should just start by doing one thing at a time instead of trying to worry about everything together. Migrating is a big decision and yes, there are tonnes of things to do. First off, you will need to apply for PR and that itself may take a while. If you and your hub is seriously considering that, why not look into that first and sort out all the other stuff slowly along the way.
Regarding rentals etc, best to have a budget first and look at possible employment opportunities. Most time, you will find that it is tough to apply for jobs while you are still in SG. I dunno how that will affect your finances and rentals market is increasing year by year, esp in popular areas (e.g. near city, beach, good sch etc). Can check out realestate.com.au to have a feel of the prices. Popular areas asians are mainly in the east, like Boxhill, Doncaster, Glen Waverley etc. If you are looking at near beaches, there's St Kilda & Brighton etc. All these areas are pretty ex, again, i dont know your budget so you probably have to check the websites to get relevant info.
Cant really talk about schools since my gal is not going to be in Pri sch anytime soon and in the meantime we are staying in the city. In any case, good luck. Sounds like you still have plenty of reservation which you probably need to discuss as a family with your hub and parents etc. All the best!