If you do some google searches you will find a lot of info on Dutch Oven cooking. Using regular charcoal briquettes instead of campfire coals lets you regulate the heat a lot easier. Many recipes you find on the net will specify how many briquettes under and on top of the oven.

Be sure to use nothing harder than a plastic scrubber with boiling water to clean your oven, and always coat it with oil after use. If you get a spot of rust inside, Coke will eat it off (and we drink that stuff!)...