There are three basic types of lighting:
Table lamps and floor lamps should have a distance from the bottom of the lampshade to the ground of about 36-47 inches. This height will prevent direct view of the lightbulb and will give ample reading light. You can use different sizes of harps to achieve the proper height.
A chandelier should be hung about 30" above the table. Too often, chandeliers are hung too high and seem disconnected from the table. For ceilings that are nine feet or more, a two-tier chandelier would work well to fill the space between the ceiling and the table.
Dimmer switches are terrific for dining room chandeliers in particular. You can dim the light to create a nice ambience when entertaining.
Of course, lighting your home is important on the outside as well since a good lighting plan will add visual appeal and value to your home.