Here is the idea:

You first construct the pulley with wooden blocks (chance of breaking) or you make a more permanent pulley out of iron. You then attach a rope to it in your inventory along with more wooden blocks/sticks to serve as an arm over the ridge. You then climb to the top of whatever ridge you're trying to get your object over and right click the pulley onto the edge. This will install the pulley and lower the rope. You then climb back to the bottom, pick up your item and right click it to your rope to attach it. (This is done easier with 2 people to save climbing) After this you just climb back to the top and pull your object up over the edge, collect your pulley rig and continue on.
Wooden pulleys can lift less weight or have a chance of breaking and damaging your item when it falls. Metal pulleys work at full weight and will not break or have a higher success rate.