Trees for Life is a SA based organisation, with useful resources on its website. Links to 2 of these are provided below.
 
Photos of a range of environmental weeds with links to fact sheets on each
https://www.treesforlife.org.au/bushland/bush-life-resources/environmental-weed-profiles
 
Weed management fact sheets for Monadenia (African Weed Orchid), Perennial grasses and drill and fill for feral olives.
https://www.treesforlife.org.au/bushland/bush-life-resources/weed-management-fact-sheets
 
Field Naturalists Club of Victoria Facebook page – many interesting posts about plants and animals
 
Greening Australia offers courses and events such as “Greater Glider Spotting” in Victoria – Their “Habitat Conservation and Management Course” - 16 weeks of 3hr evening classes and 8 full Saturday field-trips, was recommended by Sarah Patterson
https://www.greeningaustralia.org.au/training-and-events/
 
Bowerbird: A website to share and discuss Australia’s Biodiversity
http://www.bowerbird.org.au
 
Atlas of Living Australia – collaborative national project for biodiversity data. Need to check records as anyone can post a sighting.
https://www.ala.org.au