I had a quest mod suggestted to me the other day by another gamer. QuestHelper is found at Curse Gaming's site. It will consider the quests you have, place them in an order to finish them in a time effecient manner and guide you to the objectives. When I am questing, it is very helpful. When I am not, I shut it down. Anyhow - I am including the link to its download site so you can try it if you like.
http://wow.curse.com/downloads/details/9924/
http://wow.curse.com/downloads/details/9924/