Cannabis is the most commonly use illicit drug in north america, it has a lot of names, some of them are: weed, hash, pot, grass, Mary Jane, herb, joint, 420, blunt and many more. Three species are recognised, Sativa, Indica and Ruderalis.
Around the world is mostly illegal, check your local laws about cannabis. The main cannabinoids are THC (which is the one that makes you high) and CBD (mostly found in medicinal marijuana).
What can I expect?:
If you are using it for the psychoactive compound THC you should expect good mood, laughing, forgetting things, mumbling, hunger, paranoia, red eyes, visual and auditory hallucinations, increase hearth rate, dizziness, dry mouth, slow reaction time.
If you are using it for the non-psychoactive compound CBD you should expect some medicinal properties like anticonvulsant, antipsychotic, anti-inflammatory, antidepressant, antianemic, antioxidant and antitumoral.
Doses:
There are no doses and you can't overdose on marijuana. Cannabis hits everyone different, so experiment yourself to see what dose might me appropriate for you.
Smoked:
The total duration is 1 - 4 hrs, the onset is 0 - 10 mins, coming up 5 - 10 mins, plateau 15 - 30 mins, coming down 45 - 180 mins
Oral:
Usually is in form of edibles, since raw marijuana is non-psychoactive. The total duration is usually 4 - 10 hrs, the onset is 30 - 120 mins, coming up 30 - 60 mins, plateau 2 - 5 hrs and coming down 1 - 2 hrs
Hangover:
The effects of the hangover for cannabis are dry mouth, tired, red eyes, foggy, slow thinking and reduced memory skills.
Sativa vs Indica:
And remember, always consume cannabis in a safe place where you feel comfortable.