@dfoster85 - They come in different shapes. Most are round for making round loaves, but you can also get oblong-shapes ones for making long loaves of bread. I would suggest starting with around one. They're a little more versatile, I find--you can also use them for baking meat, fish, etc.
If you've never baked with stoneware, you're really missing out. Nothing else is going to cook so evenly and give you such nice texture. I almost never use anything else anymore. I even bake cookies on an oven stone.