Are there any laws regarding this. I'm not an agent or anything but I have marketing and salesman experience. Will I be able to list my home privately on websites such as Realestate.com?
Yes you can sell your own house. There are various companies that can assist you with signage and advertising your own place.
Here are links to two websites that provide such a service:
You can even advertise directly on Domain.com.au and do your own signage.
By the way you can do your own conveyancing as well.
You will not be able to list you property on Realestate.com directly, but there are "low service agents" who will list it for you.