My brother-in-law is an avid camper. He uses a dutch oven all the time. His formula for heat is to use charcoal, and to count each for 25*. He puts 2/3 on the bottom of the dutch oven and 1/3 on the top. So if you want to cook at 300*, use 12 bricks, 8 on the bottom and 4 on the top.

His recipe for a quick camping dessert he calls dump cake is:

1 instant cake mix
1 squirt or 2 or 3 of liquid butter
1 can fruit pie filling - cherry, apple, whatever

Mix and put on the charcoal. It usually takes 20-30 minutes.

Chuck