Here we go with another rule of thumb:
For hand-held shots, USUALLY (depending on the shooter, etc.) one would not want to go longer than the reciprocal of the focal length.
So for a 50mm lens, you would not go longer than 1/50 of a second.
For a 200mm lens, you would not go longer than 1/200 of a second.
And so on.
Some people can hold a camera with less "jiggle and shake" than others, and some people will have to brace the camera on something nearly all the time.
For animated subjects, (people, pets, etc.) use shorter shutter times.
For still life you can put the camera on a tripod or brace it and go with a longer shutter opening.
So it all kind of depends.
edit; I realized that I wrote shorter but now have changed it to longer. Sorry.