Hi Kirbay,
That is a lovely thing you are thinking about. I know a bit about this as we are currently looking for an egg donor. I am hoping to advertise soon on BB actually.
As far as laws go, each state has there own laws but the laws are not really very stringent, it is the clinic rules that are more stringent. The main law is that in Australia it is illegal to ask for payment for egg donations (or organ or tissue or anything else)
Most clinics say donors should be 35 or younger and preferably finished their own family. This last requirement is because their is a slim chance that the donor's own fertility could be affected by the hormonal treatment they have to undergo. Because it is relatively new I suppose there could be long term effects not seen yet. But if you want to donate and have not finished your family I think in the end it is up to the donor. I have heard of a few young women not started their families yet, donating to their sisters or cousins.
WA has a rule that there is a 6 month "cooling off" period I think, Just to make sure no one wants to change their mind.
I could rattle on forever but I will PM you a link to a site I have joined about it all.