You want to mount the motor so that it's zero is aimed at your true south satellite. Also, you MUST make darn sure that the pole is absolutely plumb. If you have a level, test the pole on both north/south and east/west axis as well as nw/se, sw/ne just to make sure... and make sure that it ain't gonna budge at all. Being just a fraction of an inch off of plumb can cause the ends of the arc to be be off. When you finally get true south, tweak motor to get good signal on ts... but then also tweak on ends of the arc.... Uh, when mounting, basically you mount the motor, leaving the C clamp sort of lose enough to swivel the entire motor. You don't change the motor's position at first startup when you get going since you want it zeroed in on true south. When trying to find ts, attach coax direct to the lnb and forget about the motor til you are on ts so that you don't accidentally activate usals or diseqc and move off of zero on the motor. Later, you can put the motor in the loop... hooking it up, when everything is done goes from receiver -> motor->switch->lnb, unless you are using a lnb with only one out, in which case the switch is not necessary... I have an invacom quad, which is why I need the switch.
I am not 100% sure, but since you are due north of me, which I think you are pretty close 93 might be your ts. When you get the motor mounted, I find it easier to swivel in to ts, roughly finding a strong signal... then tweak elevation on the pole coming off of the motor - not on the motor itself... it's easier to do it that way since the motor should be set at your lattitude setting, and the offset should be on the other - it's a lot easier to lift the dish mm at a time or so then it is to lift the motor to adjust elevation... skew on ts should be straight up/down and the motor should be able to adjust the skew on its own as it moves through the arc. You will probably need to tweak lnb location just a smidge to tweak in arc's outer edges, like on 123 g10r, and on the other side of the arc... You can use usals for most of the arc, which makes things a lot easier than diseqc, but far ends of arc, for Hispasat, and a couple of others may need to use 1.2 instead... Just make darn sure that mount is totally plumb. I have a mount on my roof from Soudon that's suppossed to give absolutely plumbness, but I found that after several months of motoring around, it fell out of plumb a little... I finally fixed that a few weeks back by putting a couple of extra screws on the roof just to the right of and above the mount, and ran some copper wire from the screw to the mount to nudge it in to absolutely perfect plumbness. I like that way of doing things since if it rusts out eventually or whatever, I can go back and just add more wire, preferably a bit more weatherproof, down the road. You probably won't have the problem since I think you'll be mounting in to the ground, but either way, make darn sure the thing is 100% plumb if you want to get the full arc at as good of a quality as possible. Adding some extra lines to the ground around the pole, like you'd see going off of a tent to hold it in place, might not be a bad idea, if the pole isn't dead on plumb on level in all directions.
Have fun setting up your motor.