This article is from the Model Rockets FAQ, by Wolfram von Kiparski with numerous contributions by others.
The C.A.A. RULE (Paraphrased from regulation 295):
No model may be flown over 300' without a waiver from the
CAA. Only matters relating to airsafety shall be considered in
granting a waiver. Further, you may not launch at all within
5km of an aerodrome (airfield or airport). Also, some states
have explicit age restrictions (ie Queensland - Minimum age 18yo),
and fire restrictions (Qld again, must have local fire marshall
approval). You should also respect fire bans as a matter of
safety, courtesy and good public relations.
Other than this, you should follow the standard _model_
rocketry rules of the NAR, and note that only engines up to
"D" class are available.