We were all rookies at some time--I was less than two years ago. I was reluctant at first to ask basic questions here but found that folks were patient and willing to offer great advice, which I still ask for . . .
As for leveling, we've found that Andersens work the best. (I will, however, never buy from this company again. The owner vandalized a natural arch in Utah and offered, in my opinion, an insincere public-relations apology. There are, it seems, good Andersen-type levelers out there.) Rolling up on these levelers is sure easier than working to build those pyramid-shaped forms with the "lego" pieces, as we did before getting the Andersens.
We use the "lego" type blocks under the three jacks. As reported by others above, they reduce how much you need to extend the jacks, keep the ends from sinking into soft ground, and provide peace of mind that you won't be damaging the jacks should you forget to retract them before pulling your trailer. We use Tri-Lynx levelers and caps to build these blocks.
After reading Mike's post and viewing his photo, I just put this into my Amazon shopping cart: Camco Yellow RV Wheel Stop-Stabilizes -Large (44622). These, in addition to our Camco Wheel Chocks, will provide extra stability and peace of mind that we won't be rolling off off the Tri-Lynx blocks or Andersens.
Note: While I admire those who have built their own blocks to put under the stabilizers, I like that the Tri-Lynx are lighter weight than wood. Like Geronimo John, we store our blocks (Tri-Lynx) in a milk crate along with the chocks. The Andersens are pretty heavy but fit well in the "curve" of the basement compartment.
Happy leveling and stabilizing.