[reible]

i've bought a pin for pin routing and have seen pictures of pins on both sides of the router bit and was wondering what is the correct position? is it supposed to be at tthe leading end or the trailing end of the bit?

I think you are talking about a safety pin that goes into a hole in your router table and if so then it is on the leading side, you go against the pin then engage the router bit. This is used with bits that have bearings and you do not need to stay against the pin after you have started the cut.

"Pin routing" is as Tom says is always with the pin aligned with the bit. The pin is either mounted on an overhead arm, or, on the table with the router mounted overhead.

Ed