^^ Maybe this belongs in Australian Drug Discussion?
Although not the safest way, I learnt purely from the internet. Here are a few resources for you:
www.shroomery.com
Lots of information on magic mushrooms. Make sure you check out the forum as there is lots of information on mycology and hunting. Members will also do mushroom IDs for you if you follow the ID guidelines.
http://www.shaman-australis.com/~bluemeanie/index.html
A small but useful site showing most of the magic mushrooms found in Australia with some pictures.
http://www.erowid.org/library/books_online/magic_mushrooms_aunz/magic_mushrooms_aunz.shtml
An excellent free book on magic mushrooms in Australia
http://www.bluelight.ru/vb/showthread.php?s=&threadid=80881&r=27
A thread listing mushroom books etc.
By doing a search in the Australian Drug Discussion Forum you will also find several helpful threads on mushroom hunting.
I would recommend getting a book or two and doing lots of internet research. Also, see if you can organise to go on a hunt with someone, as you will learn a lot. Even if you feel that you are ready, be very careful picking your own mushrooms. A chance to trip is not worth your life and magic and dangerous mushrooms can look almost identical.
I don’t know about classes but maybe someone else can help you.
If you put the time and effort in and play it safe, it is definitely worth it. Good luck!