Queensland has a reputation within Australia for the harshest cannabis laws. Curious, as Queensland also has a reputation for harbouring the biggest cannabis users. Drug laws in Queensland are governed by the Drugs Misuse Act 1986, possibly one of the most obfuscated pieces of legislation in history. The disclaimer still holds, I have no legal training or expertise, if you're in trouble call a lawyer yada yada yada.
It seems that in Queensland all marijuana offences are indictable offences, but some may be treated summarily. A general rule is that if the maximum penalty on conviction is 15 years or less, then the charge may be made summarily. A person convicted of a summary offence is liable for a maximum penalty of A$6000 and/or 2 years imprisonment. All penalties for indictable offences may be supplemented or replaced by a fine of up to A$300,000.
The maximum penalty for simple possession of marijuana is 15 years imprisonment for an amount less than 500g, otherwise 20 years imprisonment. Possession of anything for use in connection with consumption of cannabis carries a maximum penalty of 2 years in prison.
Permitting your home, office, warehouse, toilet etc. to be used as a marijuana smoking venue has a maximum sentence of 15 years in prison.
Cultivation of less than 100 plants with an aggregate weight of less than 500g carries a maximum penalty of 15 years imprisonment. Any more than that and it becomes a maximum of 20 years.
Queensland law draws a distinction between normal supply and aggravated supply. The offence is one of aggravated supply if the offender is over 18 and the person supplied to is under 18, is intellectually handicapped, is within an educational institution, is within a correctional institution or does not know he or she is being supplied with a drug. Aggravated supply carries a maximum penalty of 20 years imprisonment and normal supply carries a penalty of up to 15 years imprisonment. Carrying on a business of cannabis supply carries a maximum sentence of 20 years imprisonment. Receiving or possessing property from aforementioned business has a maximum penalty also of 20 years imprisonment. I am unsure of whether you could be tried for all of these charges at once, but I assume it's possible.
Sources:
Drugs Misuse Act 1986
Drugs Misuse Regulation 1987 | 
