Shown are two methods of drip irrigation for your container garden. The first is a standard system shown in the following video.
Next is a rather inventive pop bottle irrigation system from the Chicago Garden at Chicago Now.
Use a 2 liter pop bottle, or whatever size is right for your container. Poke small holes in the bottom, fill with water, then screw the cap back on to keep bugs and debris out of the water reservoir. Place the bottle in the soil and it will slowly water your plant. You can place rocks in the bottle to keep it from blowing away when it is empty.