Most people believe that boiling water is the best way to remove all impurities, including salt. However, this isn't necessarily true. While boiling water will evaporate some of the water, it won't remove all of the salt. In fact, depending on how long you boil the water, you may actually end up increasing the concentration of salt.
If you're concerned about removing salt from your water, reverse osmosis is a much more effective method. Reverse osmosis forces water through a semipermeable membrane, which removes most impurities, including salt.