Q:

Is there any easy way to find a quest destination ? 

The map doesn't always help me find my destination and I sometimes end up wandering.  
Is there something I'm missing ? 

A:

If you're extremely distant from the objective, the Waypoint system will indicate the closest node with a yellow chalice icon.   When closer, you can hit Tab to pull up the map overlay and drag it around to find a direction/destination.