Grind your coffee beans to a medium to fine consistency.
Wet your Chemex filter with warm water. This washes off the pulp which you don't want to taste in your coffee and helps the filter stick to the glass.
Put about 3 to 3 and half tablespoons for a 3 drink Chemex (like this one).
Boil your water to between 190-205 degrees (your kettle will boil to about 212 so just let it stand for a bit so it cools). Pour a little water in the Chemex and let it stand for 45 seconds.
Fill up with water about half way to two thirds up. I do this in a bit of a circular motion to bring in the coffee from the sides.
Repeat once the water goes down.
Watch delicious coffee drip through the filter.
When it gets to the knobbly bit it's enough for one large strongish coffee - just now I like it :)
Now enjoy your delicious mug of coffee.