where do these start? i don't remember if i asked before or not. i honestly have the worlds worst memory so i sincerely appologise if i have already asked. i am thinking that the shivering isles starts with the quest "a door in niben bay"?

Without divulging spoilers, you are given clues via pop-up messages on your screen.

I think you actually asked us this over in the spoiler section just a few days ago

Yep.
http://www.gamesas.com/topic/1342449-expansions-where-are-they-conected/

that post was actually a day after this one