Okay dude, I am just gonna tell you some tips on how to research things. Since it seems you have no clue.
Go rent some documentries, go check out some web sites...go look for some information with GOOD credible sources...read some books...some magazines.
I could go on for days.
Not only are these good ways to find more about weed, but it is also a good way to find more about ANYTHING!!! GOOD LUCK with that buddy! Some people shouldn't smoke weed!