A conflict between a landing helicopter and a taxiing G-200 occurred at TEB when a hold short of Taxiway J clearance was not complied with.

Narrative

After landing Runway 19 at TEB. We were told to taxi to parking; hold short of Taxiway J and after a helicopter lands continue taxi to parking. We exited Runway 19 at Taxiway K. Taxiway J is the next taxiway heading south on L. We began taxiing on L. First officer was completing after landing checks. I did not see the sign for Taxiway J and taxied into the intersection. Ground Control asked if they were going to stop. I stopped the aircraft immediately. The helicopter landed and hovered in front of us into another parking area. We apologized for the mistake and Ground said 'no problem' taxi to parking. I do not believe there is a taxiway identification sign on the left hand side of Taxiway L when taxiing North on L to identify Taxiway J. I will stop the aircraft anytime a hold short clearance is issued and have the First Officer verify the hold short location prior to continuing to taxi. If there are not taxiway identification signs on both sides of the Taxiway L; install additional signs.