you need to setup the plow on a flat level surface.
(for the most part) a moldboard plow is designed to plow half as deep as it is wide. so a 12" plow is designed to plow 6" deep.
Start by takeing a 6x6 block and driveing the LEFT tire up on it. (tilting the tractor to the right) this simulates the angle the tractor sits at when your plowing in the field with the right tire in the furrow.
then its a simple matter of aligning the 2 plows to sit level on the ground behind the tractor. The plow share (the front part that cuts the dirt) needs to sit level left and right. Adjust this by adjusting the sidelink on your 3pt.
the front points of both plows should engage the dirt at the same time, You dont want the front one leading the back one because it will have a tendancy to dive the plow to deep. your second moldboard doesnt cut as deep. This is the top link adjustment.
Coulter wheels should be adjusted to be about 2" above the share, and inline with the frog.
the last adjustment is the side to side offset of the set of plows. as looking at the back of the tractor, the far right point of the front share, should be just at the inside edge of the right rear tire. To far right and you arnt makeing full use of your front plow, to far left and technically arnt flipping all the dirt leaving a small patch un-tilled.
Last is the speed at which you travel. If the sod/dirt doesnt want to flip your going to slow, if it wants to continue to roll another 180 deg, (with the face that was org up, up again) your going to fast. for the most part this is roughly 3mph (ive heard a range of 2-4mph)
After a few rows have been tilled, you can fine tune yoursetup. if the bottoms of the furrows arent flat, your side tilt is off slightly. (make small adjustments)
If when looking back and both plows dont seem to be flipping the same amount of dirt, or your constantly fighting the plow nose diveing, lenghten your top link. On the other hand, if you cant get the plow to start into the ground, and it constantly wants to ride up out of the ground, you need to shorting your top link. (again small adjustments)
If your rows dont seem to lay ontop of each other right, your side shift is off.
[ame]http://www.youtube.com/watch?v=aIMqPy6DxSw[/ame]
^^^mysetup is almost dead on except my side shift is slightly off, but thats harder to get correct with fat R4 tires instead of classic R1's. mine is a 2x16 dearborn