Moka coffee is brewed using steam pressure to push water through grounds on a stovetop. While it produces a rich, intense coffee similar in body to espresso, it is not true espresso because it lacks the 9+ bars of pressure required to create the characteristic "crema."
Deciding on a pot involves choosing between traditional aluminum (which develops a seasoning over time) or stainless steel (which is easier to clean and non-reactive). Consider your stove type—induction stoves require a specialized steel base—and how many cups you typically need to brew at once.
Start with fresh coffee ground to a medium-fine consistency. Use pre-heated water in the base to protect the grounds from overheating. Fill the basket level with the rim—never tamp the grounds. Brew on medium heat, and as soon as the coffee begins to flow, turn the heat down to 1/2 or 1/3 intensity. Remove the pot from the heat during the "violent sputter" phase to ensure the best flavor.