A bird feeder is only one way to bring wild birds into your yard. You can also attract them with a bird bath. Birds will come not only to bath or splash in the water but also to have a drink.
No matter what style or design you choose for your bird bath, it should be no deeper than 3 inches. The edges should be clear enough for perching and the bottom should be sloped towards the sides. Many cheap, commercial baths are made from plastic, which can actually be too slippery for smaller birds to use comfortably. A rougher surface is better, like stone or terra-cotta. Small stones can be placed within the dish of the bath to improve the traction and to give more perching opportunities.
Keep the water fresh and the bath clean. You should refill it every 2 or 3 days with clean water. Not only is this better and healthier for the birds, you will be preventing mosquitoes from laying eggs in the still water. Another way to keep the water from getting stagnant is to install a small fountain or drip system. Birds are always more attracted to dripping water than still water. If you have a problem with algae build-up, change the water more often. Don't use chemicals to keep the water clear.
Heated bird baths are more elaborate (and expensive) than the simple dish-styles baths, but these will keep the water from freezing in the winter and will attract birds all year-round. A heated bird bath would make an excellent choice for people living in northern climates that have several months of below-freezing temperatures. Wild birds can have a difficult time finding water to drink during the winter. You can purchase bird bath heaters that will work with your regular bird bath, if you don't want to buy a new bath altogether.
Bird baths can be placed directly on the ground, but they will attract small mammals and even cats in such a position. Needless to say, having cats at a bird bath won't help attract birds. You could place your bird bath on a pedestal or even hang it from a tree instead. A bath placed under a tree with overhanging branches will be more appealing than one sitting out in the open.