Quest helper addon will give you a list of quests you completed, you did not complete and ones you can complete.
It also gives you closest objective (be it to kill mobs, complete quest or talk to someone) and all info required to complete quest.
Also, while holding mouse button it tells you how much XP/TP you will get once all quests you have started you complete.
Did I forgot to mention there is also pointer on mini map which points to closest objective?
In absence of Rustypedia on all servers - QuestHelper is your best friend!