Hey
You can do either a child care certificate course (about 1 year) or specialised nanny courses. Yes, you also need your first aide, police check and expereience/refereneces.
I worked as a nanny before having ashlea, then worked for another family taking ashlea along, but that family came specifically to me and asked me to work for them. Because I was in a position where i didnt need the work, i could make all the calls, and said i would only do it if Ashlea can come cause I refuse to work more than 2 days a week without her. They had no problem with it at all.
The problem is that not alot of people want you dragging your kids there too. They like their children being your priority and see having your child there as their own missing out somewhat. They are paying you to look after their kids, not yours, IYKWIM?
Agency's would never advertise a mother nanny, and like the experience or certificate. They usually pay between $14 -$18 a hour depending on how many kids, ages etc
You could advertise babysitting, but once again, not sure if people would want you to bring your own child. If you get an understanding family its great.
Home care is a great idea, not sure about the qualifications, i think they need references and a police check and first aide Cert. If you do it through the council then they have to come and check your place to make sure its up to standards, sometimes you have to do a few things, gates to the kictchen, check fences etc. They pay is less than babysitting or nannying, but for stay at home parents, a lot more suitable.

Good luck with it all!