Being in Australia I presume I think he will find these sites most helpful:
www.nkn.com.au (website of top Aus Mag)
http://www.austkarting.com.au/ (the official karting website of Aus)
On the second website there is a section dealing with getting started, click on it!
As far as costs, umm.... How far does he want to go?! Some spend a fortune. Sadly, that it what it takes to be at the front in most classes.
karting in Aus is going through a weird and rough stage. I'm dithering over the prices and politics of it all....
Hope that helps.