Types of Water Dishes
BowlsThe easiest solution is the stand still bowl next to their food. It should be changed daily, and often. Make sure it is clean. Keep in mind the water levels to indicate a possible problem with water intake.
Automatic Water DispenserLarge and similar to the Automatic feeder. This continuously makes sure that there is a somewhat fresh scource of water for the cat. Usually with a filter, the water does need to be changed out often along with the filter. The levels of the water are easy to see with a clear plastic top.
The FountianA plug in unit that cycles the water so there is a constant cycle of fresh clean water. These can be used when you want to break your faucet feline of their finicky habit of needing the water flowing in order to drink. These come in a variety of shapes and sizes and prices. Remeber function over fancy. Its also a little harder to moniter your cats water intake.
The BubblerSimilar to the fountain, this is a a plug in unit that bubbles the water creating oxygen to make it fresher. Keep in mind, this one does make noise and some cats are scared of it.