If you want fast levelling at 10, then go to Kurns Tower or Paludal.
In Kurns, just zone in from Field of Bone, and pull the mobs right at the zone line. They will be tough at first, but very good experience. This is good up to 18.
In Paludal, use the entrance in Shadeweavers Thicket and move in to the first pool. Kill there, then start to move deeper in up the east passage. There is a clean progression of levels up to 22; at 17, you should move to the shiknar, which are best reached from the Hollowshade Moor entrance. If you want, at 22 to 25 you can move to groups at the Shadowhaven side, killing bandits. But some people don't like the groups there.