The best way to get a soil sample is with a soil probe. They can be purchased online for about $50. Take 6-10 cores that represent your plot down to 6-7 inches. Mix the soil well in the bucket. Do not sample area that are out of the ordinary- dead tree roots, animal dropings, old roads, etc. If you do not want to buy a soil probe, use a hand trowel to take your samples. If you use a trowel, TRY to get an equal amount of soil from all depths into the bucket. The best soil testwill be done bya lab in your state. They will know what kind of test to run based on the soil normally found in your area. I would tell them the crops you want to grow, and not pay extra for the "wildlife plot" tests. They run the same tests, but just charge you more. Look online for a lab, or ask your county extension.