What is their role? To help with financial control of your money and/or assets, to help with investments
What do they do? They can do as little or as much as you like them to do. So if you want some guidance with your super, they can help. If you need some assistance with managing your money and/or assets, they can help. They can help you sort your life out financially.
Where do I find a good one/what should I be looking for? Finding a good one, best thing is word of mouth. Failing that, shop around. The bigger companies are not necessarily the better companies.
Do they cost money? Yes. There is no flat rate for a fianancial advisor. I know some banks (usually the big 4) have financial advisors. I'm not sure that they charge a fee though. But private ones certainly do.