First of all, you should use a machine like this one beside.
Aluminium is probably the best material; you shouldn't use a stainless steel machine. Take care that the water marks the level of the external valve of the boiler. You should fill up the filter making a cute small hill of coffee just over the superior edge. Don't press it with a tea spoon: this would be a mistake. Then simply close kindly the machine.
Few words about the coffee: It should be ARABICA quality: the best one.
For example, I like a lot the coffee from Nicaragua traded through the organization Equosolidal Fair Trade .
As personal taste I'm used to sweeten exclusively with some honey. In general to have a good performance your Moka should work frequently or even daily. Don't wash the Container inside using detegents but use only water, don't leave the boiler for a long time wet inside because in the long term aluminium reacts with water producing aluminium salts not really healthy. Finally coffee should be conserved at best in the fridge in a glass or aluminium box but well closed to preserve aroma.
it's wonderful sniffing the aroma of the first coffee springing out into the Container with your nose very close to the edge of the container.. wow... a real addiction especially in the early morning