where do i get the stuff for the poison?
What, the ingredients? Plants, mostly, as well as some creatures when killed. Harvesting any plants you come across is a good rule of thumb to begin with, 'till you get an idea of which are the most useful for your character, and even useless potions can be sold for profit. You can also buy ingredients in alchemy stores (there's usually one in each town as well as a vendor in each mages' guild hall, though there are exceptions), as well as some (primarily foodstuffs) in inns/taverns.
edit: am slow again.
Somebody like me who wants to give information, but doesn't want to read other info that'll screw up her game!
I was only offering information that can be inferred from the manual/loading screens, but I didn't mean to upset anyone, apologies.