Interesting hike as you get to experience a variety of terrains and pure nature if you decide on the premium trail. We got down at Calw station. Took a walk through the city and to the muncipal park. At the end of the park you'll find sign boards that help you find your way. The outdoor app really helps here because it guides you with great accuracy. But there is also sufficient signs throughout the trail. The uphill climb at Stubenfelsen is the hardest and most demanding.
Important pointers: You can decide to quit the hike once you reach Wanderheim. But warning the last bus leaves there at about 18:00. If you miss that then it's about 5km hike to the train station. The other option is to follow the trail back to Calw.