I am sure others will have useful ideas but as a starting point

http://www.pristineantiques.com.au/collectors-clubs

has a handy list of collecting clubs. Some may have their own web site, others may have a magazine, or may be able to put you in touch with enthusiasts in your own geographical area. There are 2 regular Australian antique collecting magazines that I know of, and several on-line reference repositories where you pay a fee to access information. I am sure everyone would agree that the best way to learn is by handling, but as you are buying and selling, you must be doing this already!  There are some remarkably informative specialist web sites out there - people are often very generous with their expertise.