Hi there, I had a baby in Sydney a year ago. Must say I felt completely out of my depth to start with but as time has gone on I have been so impressed with the services and resources available to new Mums here. In terms of buying things second hand, I did get a lot on Gumtree and Ebay, there is also something called the Baby & Kids market that is on in various Sydney locations every month or so. The hospital / obstetrician / doctor generally put you in touch with pre-birth info and resources, and post-birth there was a Early Childhood Centre at the local shopping centre where you went for a once-weekly meet-up for the first 12 weeks (the post-birth visit midwife gave me the details). I got to know a great group of Mums through that, we all still meet weekly, and different groups have formed swim groups for the babies, dog-walking groups etc, we do 'babes in arms' cinema trips (check out the local cinema listings, most cinemas do them). Other people go to a library service called 'Baby Bounce' which is free, involves songs and rhymes, there are also quite a few churches in the area that also host meet-ups which are not religious in content. I have also been so impressed by the parents' facilities in the shopping centres. Other friends who've had baby care & sleeping issues have called the Tresillian helpline or even been for a residential visit, I believe St John of God and Karitane also offer a similar service. There's a good link here: http://www.bubhub.com.au/directory/find/early-childhood-health-centres-sydney
I think basically when you are pregnant you feel like you are pretty much on your own, especially as a new migrant, as time goes on and especially after you give birth you start to find out about all the various resources, it's been great, if your friends are sociable types they will have no problem at all. Lisa x