Try to Keep the Contrast High

Depending on the style of photography, images usually look a lot better when you view them on a black background. This is typically because there is more contrast than when viewing against white. Contrast helps bring out the colors of the photo, which in turn, makes the image appear more vivid and stunning. If you do any type of sports, commercial, HDR, nature or portrait photography, try viewing your work on black and then on white and see which one looks better to you.
When designing a dark site, its usually a good idea to have some flare of color added in somewhere. It can be your logo, or your navigation, anything. Black and white can be extremely effective, but adding a touch of color adds a touch of personality.