I've done it and I've never looked back'
check out centrelink benefits as that will help you with finances. there are additional things they have for single parents as opposed to partnered ones.
have a chat to a lawyer (there are free legal clinics) to determine your rights in relation to the children. Its also an excellent time to discuss property entitlements and get all of your ducks in a row so to speak before you separate, knowing what % you are entitled to and keeping copies of records in case he tries to hide money later.
have a safe exit plan (or a kick him out of the house plan)
a;sp there are plenty of parents groups out there its just a matter of finding one that suits you. you will find that you may make a couple of really good single mum friends and you all keep an eye out for each other.