There are two small holes in each cam that your string is supposed to line up over, it is on the side of the cams.
According to hoyt the string does not have to be centred over the holes for proper tune, just has to be over it somehow.
If you go to archerytalk there is a good write up about tuning the cam and a half somewhere. Good luck, I found it a pain in the ass to get mine tuned.
The timing is seen at full draw. The cables touching stops. Most guys find the best tune with the top stop touching cable slightly before the bottom stop.