When you mouse over your abilities it should state if it uses stamina or magicka. Generally you want to put attributes into whichever you need more. Classes as far as I can tell from my small test of NightBlade and DragonKnight are slightly mixed in magicka and stamina abilities but have a slight need for stamina more. One can assume if you went Sorcerer that you will need magicka more than you will need stamina.
This is my current stat allocation method with my DragonKnight Draconic Tank