I highly reccomend looking at the FACTS website. Some areas (in NSW) are in high demand! Others are not. Some areas have high demand for people willing to take babies, teens, disabled children etc. It depends a lot on your personal circumstances, abilities & location wether you will be placed with a child.
Foster care is an incredibly difficult & equally rewarding thing to commit to.
You accommodate foster children as you do your own however you need to remember one day, these children go home (ideally & if suitable) and at the same time, you may always play an important role in their lives (age & family dependent)