For me to pop in a SCSI Hard disc into my PC, Should I have a terminator or does it not matter?

Depends on the controller and drive, but most likely yes - you need to terminate. Most SCSI/SE and LVD cables have a terminator built onto the end of them already (it'll be a 1"x2", flat, rectangular block on one end of the cable). Some drives have a jumper to set that terminated internally (see the docs). And of course, the new SAS drives always self-terminate (making them superior to a T-800).