There is some dispute over whether or not soaking beans before cooking is necessary, and there are certainly some advantages to taking this step. Technically, however, it is not absolutely required, although when a recipe calls for soaked beans, you should take the time to soak them, as the cooking time will be wrong otherwise. There are also some distinct advantages to using soaked beans rather than dried ones that you may want to consider when preparing bean recipes.
Whether or not you soak beans, it is essential to wash and pick through them before using them. Otherwise, you may cook in pieces of gravel, twigs, and other objects from the field the beans were grown. It helps to rinse beans in a large colander, allowing them to spread out as you rinse them so that you can pick out any foreign objects. If you plan to soak the beans, cover them in warm water, changing the water every now and then until the beans have swelled to twice their original size; you can also simply leave them in the water overnight.
The primary reason people soak beans is to cut down on cooking time. Beans that have been soaked cook in much less time than dried beans do, saving energy in the cooking process along with time. In addition, by slowly allowing the beans to fill with water, you will encourage them to cook all the way through, rather than cooking on the outside while the middle remains raw and hard. Soaked beans are also less likely to fall apart during the cooking process.
Some people also believe that the longer you cook beans, the less nutritional value they have. It is true that heat damages some essential vitamins and minerals, but the beans will still be extremely nutritious. You should also simmer the beans slowly, rather than boiling them, to encourage gentle, even cooking without burning.
All of the above reasons are pretty strong arguments to soak beans, but there's a clincher: soaking helps to break down the sugars in beans that your body finds hard to digest. These sugars are the root cause of the gastrointestinal symptoms that are infamously associated with beans, and by soaking them before cooking them, you can drastically reduce gas, bloating, and other discomfort.