Popcorn comes in two varieties,
real and
microwave. The latter is easier and tastes alright, but the former is the real good stuff, although it takes a little more work. To prepare microwave popcorn, well, just stick in the microwave and
nuke it.
Now, to make real popcorn, you'll need a cast-iron pot, as listed above, and some kind of oil. Olive oil works, but I suggest using canola oil for cleanest and best results. Before placing the pot over heat, pour a thin layer of oil into the bottom, enough to just cover the entire bottom of the pot, leaving no space dry. Now, get some kernels of popping corn and place them in the oil. The kernels must be covered in oil, or else this won't quite work so well. Watch the pot closely, as this process won't take very long. As soon as you see the first kernel pop, remove the pot from the burner. This is the time to dispose of any excess oil. After exactly 1 minute, place the pot back on the burner and cover it up. You will hear the rather noisy sound of kernels popping. Once the sound begins to ease off, carefully (as there will be hot air inside) lift the cover. Have some receptacles handy, as this thin layer of kernels will produce a LOT of the final product. Pour this judiciously into receptables.
While the pot is empty but still hot, drop some pats of butter into it, and let it melt. Carefully pour this melted butter onto the popcorn and use some kind of eating utensil to mix it up and distribute the butter evenly. Now, shake some salt into the mix, and it's ready to serve.
Be sure to eat the popcorn right away, though, lest it get stale. Stale popcorn rivals flat soda and moldy bagels as one of the most undesireable things to consume.