Why do you warm a Dutch oven up before baking bread? I want to attempt to make bread in my Dutch oven. Most of the recipes that I have found say to warm your Dutch oven up before putting the dough in. I have found a few recipes that say you don't have to warm it up first. Why should you warm it up first, and will it make a big difference in the bread? And what breads are best for baking in a Dutch oven?
The point is you are actually using the dutch oven as the oven itself here--so you warm the dutch oven for the same reason that you would pre-heat your conventional oven: you want the bread to immediately go into the hot oven, instead of slowly raising the temperature. 

With a hot dutch oven, you get the "oven spring" that you would get from putting the loaf into a hot oven, and the dutch oven traps the steam that the bread gives off, so it helps keep the crust soft while the bread expands.  This is a great way to bake bread at home in ovens that don't have steam injection.