Depending on what you're cooking you will want to arrange the briquettes differently. See the diagrams here.
You can cook almost anything in a Dutch Oven... bread, meat, stew, sauce, etc.
The Dutch oven was created in the 17th century by a man named Abraham Darby. He intended the Dutch Oven to be a cheap and versatile piece of cookware.
It is a wide and heavy cast-iron pot with a tight-fitting lid, which makes it perfect for cooking pretty much anything.
Modern Dutch Ovens come in many finishes but the traditional cast-iron Dutch Oven is great for camping and cooking with coals and briquettes.