Maybe someone who's already done this will drop in to explain all of the particulars and how-to.You have a strobe that can be triggered externally via your camera's PC connection, as seen in the first photo. (This example is a Nikon SB-28dx, a circa "D1 era" pro flash.) This capability can be added to any hot-shoe flash for about $20 via a "hot-shoe to household" synch adapter. No worries.
The problem is, the sb600 doesn't seem to have a sync cord connector.For wired, you can get a pc sync cord and connect your camera to the flash (I assume the D50 has a pc outlet). If if doesn't, there are hotshoe to PC options where you put one end on your camera hotshoe and the other in the flash pc port.
Ha! It doesn't seem to indeed as shown here. I always thought all nikon flashes had pc ports.The problem is, the sb600 doesn't seem to have a sync cord connector.