Apart from the "CDAS Family" of web sites, Facebook pages and forums, there's a wide world of Australian and international sites containing more than any of us could possibly know about the hobby.  Do remember that what is true in one place may not be in another - laws, the availability of particular species, climate and water parameters vary widely even within Australia.  Feel free to ask any questions via the forum or our Facebook Page if you are in doubt about anything you read online or just need some local knowledge.  You could also suggest a link.

CDAS online

CDAS on Facebook
CDAS Breeders Award on Facebook
CDAS on Twitter

Other Canberra and District Aquarium Sites

Canberra & Surrounding areas Fish Keepers
Canberra fishtanks buy and sell (Facebook Group)
Wagga & Riverina Aquariums (Facebook Group) 

On-line Magazines and Blogs

Redfish Magazine - free, high quality aquarium magazine, Australian edition
Tropical Fish Hobbyist  - high quality US subscription magazine
AMAZONAS - high quality European subscription magazine
Advanced Aquarist - online magazine, mainly marine focussed
Practical Fishkeeping - UK subscription magazine
Under The Sea - an online radion Aquarium radio show

Australian Aquarium-Related Societies and Facebook groups

Australian and New Guinea Fish Association (ANGFA) - esteemed and very professional organisation for native fish enthusiasts.
Home of the Rainbowfish - excellent and extensive database on Australian native rainbows and blue-eyes
Killifish Australia (Facebook Group) or via the Killifish Australia Forums
Aquariumlife -  a massive and very active online community and forum
       The Aquariumlife forum for local (Australian) Aquarium Societies is here

The Queensland Federation Of Aquarium Societies
Betta Australis - Brisbane-based Betta Group on Facebook
Australian Desert Fishes - database
American Cichlid Keepers Australia (Facebook Group)
Corydoras in Australia (Facebook Group)
Fish & Reptile sales Australia (Facebook Group)
Fishchick Aquatics - Specialist Betta and guppy aquarium shop in Brisbane.  Also has a YouTube Channel. Accredited importer and quarantine facility for purchases.

Academic Sites with a Fish Focus

FishBase - enormous scientific database

Aquarium and Fish Education Links

The Australian Museum Fish Page - Excellent!
Aquariums in Education Facebook Group - Australian educators group using Aquariums in the classroom or lab
Sea Creatures of the Caribbean - an excellent discussion of Caribbean marine environments with lots of links suitable for school projects

International Aquarium Resources

Seriously Fish - large, very reliable fish database site
Wet Web Media - a large and diverse aquarium site with articles, calculators etc. - International trading site (warning: while it is possible to import fish bought on aquabid, you need to do so through an Australian accredited importer and quarantine facility - see Fishchick Aquatics above)
Cleaning and Maintaining Your Fish Tank - A site with some good setup and tank maintenance information (thanks Aaron!)
UaruJoey - The King of DIY - Youtube channel for aquarium DIY 
The American Killifish Association
Strictly Corydoras~鼠魚専門 (Facebook Group)
Pleco fanatics (Facebook Group)
Aquatic Gardeners Association, Inc. - A big site for aquatic plant enthusiasts
The Crypts Pages - information on the Cryptocoryne genus of aquatic plants (and closely related genera)
The Planted Tank - A large online community and forum
Aquatic Plant Central - Extensive blog site and forums
The Barr Report - subsciption based forum by aquatic plant guru, Tom Barr

Do It Yourself (DIY) Links The King of DIY Lots of Different Designs and Plans Another Big List of Ideas and Plans A Very Simple Airlift Filter DIY Sponge Filter Aquatic Plant Central DIY Forum DIY Overhead Filter Design