Nikon VR generally has panning detection built into the Normal setting (see here), and generally speaking for smooth panning (e.g. a bicyclist riding by) you want to be in Normal mode. Active is for when your own motion (in a vehicle and you are bouncing around) is undesirable, as opposed to panning where your motion is desirable. Using active in panning will cause it to fight against the pan motion, and be jerky as it recenters.
The general recommendation is that VR be disabled at higher shutter speed (I've read many different values, but anywhere in the 500th to 1000th seems accepted). I have yet to personally see any degradation above those speeds, but VR is ineffective above them and reported can actually do harm. I often use it, however, on very long focal lengths even at very high speed to help steady the viewfinder image (especially in windy conditions with big lenses); I think any degradation is probably lens specific and if you find the need to use it at fast shutter speeds, experiment to know if it impacts you.
Below those speeds handheld, keeping it turned on and on normal most of the time will usually yield the best general results, switching to active only in unusual situations. I also agree, however, in experimentation I see little effective difference in active and normal, though in Nikon literature it is well defined.
On tripods with the camera locked down (unless your lens has a specific tripod mode- auto or manually applied) turn off VR, it can do more harm than good, especially in very long exposures. Different lenses have different VR setup (especially later ones and especially with regard to tripods), so referring to the manual is always a good idea.
