How to reach Howling Stones
The fastest way to reach Howling Stones is by taking The Overthere Stone in the Plane of Knowledge. After you do this all you have to do is run directly south until you come across the large crater in the center part of the zone. Inside the southern end of this crater you'll find the entrance to Howling Stones.
All of the Skorpis enemies down here Harm Touch immediately after you agro them so I strongly recommend invis and/or taking it slowly if you don't have a lot of gear/some resists.
The map below shows the tunnels up close that you'll have to run through in order to reach the Howling Stones zone in. In the basement where it shows the zone in at on the map you'll find a large red globe to click on which zones you in.