Some useful links
General
AusForum - This forum is a great starting-point for Aussies who either have a cable modem or are considering getting one
Whirlpool - Whirlpool is an Australian broadband news and discussion portal, which also has some very useful information including an Australian Broadband FAQ
AUSBUG - The Australian Broadband Users Group
whatis.com - A useful glossary of technical terms
Cable modem providers
Optus@Home - The better of the 2 cable modem providers, because it's much faster, much more reliable and doesn't have a login client
Telstra Bigpond Broadband - The other cable modem provider in Australia
Networking
Practically networked - Lots of good information on home networking, including information for Macintosh users
Internet connection sharing software
Sygate - The most popular software
WinRoute - The most powerful software that I've seen for home use
NAT32 - The cheapest software I've seen
Security
ZoneAlarm - The free personal firewall that I recommend
TINY software - The homepage of TINY Personal Firewall, another free firewall
Gibson Research Corporation - Steve Gibson provides a port scanner to test your firewall, a program to rid your computer of spyware and various other useful things
ADSL
Greystom's page - Greystorm has a nice page explaining how to share a Telstra ADSL connection