Apart from main quest and Winterhold/Thieves guild, where can I find other long questlines (i.e. not take book x or kill y and come back for reward)?
I am having a lot of fun doing the Companions quest chain. They are located in Whiterun on the east side. They are inside a large house in the court yard where the tree is in the center. It is up a small set of steps. Its called Jorrvaskr. I wont spoil anything for you. Have fun with them. Lots of great story telling there.