I've been a carer with FDC for about 13 years. I started as an opportunity to earn money for my family whilst staying at home with my son. I really didn't like leaving my own child to go to work (but that's my personal opinion and I know that everyone is different). I had a couple of years off with the birth of my second son and came back when he was about 3.
Financially - can be very rewarding - depends on how many hours you put into it, how many children you can have extra to your own, this number varies by state (NSW allowed 5 under school age plus 2 school age) There is a lot of paperwork so get a good accountant, there is a lot you can claim on tax. Ring around schemes in your area and get lots of information.
Mostly schemes are de-regulated and carers are free to set their own fees, however there are some that have set fees.
Start out with shorter hours, it's easy to add on more hours and kids, but harder to take away hours that families are already using.
It can be quite tiring, takes a lot of organising to get your day to run smoothly, and often parents will muck things up by bringing little johnny late, just when you needed to go out. If you have help at home, older children and partner, and they will help you, you should be fine.
I always think of it as a life style change, your own child/ren need to get used to sharing toys, house and especially their mum. But saying that, it's a great way to spend time with your own, mine are really well adjusted kids, and both will sit on the floor and play with the littlies. Sometimes school events have to be missed, there are just somethings you can't take FDC kids to, Most importantly - network with other FDC Carers' it is often an isolated job and others may have ideas you can work with.
GOOD LUCK