Mike,
   I believe the 4240 plow is a trailer plow.... I have one and I forget which on it is at the moment  <!-- s:roll: --><img src="{SMILIES_PATH}/icon_rolleyes.gif" alt=":roll:" title="Rolling Eyes" /><!-- s:roll: -->  . Does yours have a hydraulic cylinder for lift?
     When the plow is in the ground, it should be running level, both left to right and front to back. It will pull with a lot less effort when it is adjusted correctly. After awhile you will be able to tell without looking if the plow is running smoothly... just by the &quot;feel&quot; of your tractor. 
 The plow depth should be roughly half of the plow width, i.e., a 16 inch plow should be running 8 inches deep.I know others may be in disagreeance with this, but this is/ was what the plow manufacturers recommended.
  It will also pull easier and the soil will turn over better when the moldboards are shined up. If the soil is sandy they will scour quickly, otherwise using  a wire wheel or the like, on the moldboards before you begin, will speed things along. Eventually they will take on a mirror shine. By having these shined up, the soil will be less prone to sticking on the moldboards. When I am finished plowing for awhile, I grease up the shiny surfaces so that they scour rapidly the next time out.
  How/where you begin plowing will depend on your field. If it is only 3 acres, you can begin on the outside edge, running the length of the field and come back on the outside of the other edge of the field. You will be turning over the soil to the outside of the field. On each successive pass, your right tire will be in your previous furrow. When you reach your last passes, you should be pretty much in the center of your field and will have a dead furrow left.... no big deal, a disc harrow will pretty much fill it later. Remember, run your plow level. When the wheel drops into your furrow, it will tip to the right so will have to be adjusted back to level once more. Your furrow should have a smooth bottom and be level left to right and have a good vertical furrow wall. Next year reverse  the process, begin in the middle of the field and and work to the outside. This will prevent a depression from eventually forming in the field. All that being said, when we plowed a side hill we always plowed throwing the soil to the uphill side.This slowed the soil from working it's way downslope. If your field is quite wide, you may want to divide it into sections and plow a section at a time, otherwise you will be spending a lot of time driving across the headlands to make the return trip on the other side of the field.
   I am sure I am forgetting things, but I am sure someone will fill in a lot of things I have overlooked.
  If there is an old retired farmer near by, you might ask him about moldboard plowing... most all plowed that way years back and I am quite sure they would be tickled to come out and give some pointers.
   Best thing is ... go out and try it. Above all, have fun!
            Cal