I made some kalua pig this weekend in my smoker; the recipe will be posted soon. In the mean time here is an excellent article that I found that takes you through the process of making your own Hawaiian-style underground oven also known as an imu. Not only does this article show you how to build an imu, it shows you how to cook with one. Enjoy.
Also, see the Kalua pig recipe.
…and yet some other BBQ smokers here