CAREFUL! BOILING WATER! I use water from the espresso machine (it's got a button and a spout for just water. Comes out screaming hot). You could nuke water, use a kettle, whatever. It's important that you have a bit more water than you want coffee and it should be pretty hot. Slowly and carefully pour the hot water into the top of the device, until it's just about to the rim. It should drip brew pretty quickly, actually. As it empties out, add more of the water until you've added it all. Revel in the lovely smell of fresh brewing coffee.