High Key and Low Key
High Key and Low Key light are two approaches used in studio photography that are used best with a single light source (and possibly a reflector to fill in some of the shadows). Low key light is created by setting the exposure for the brightest part of the pictures. This results in a picture with very dark backgrounds. High key light is created by using the same lighting setup and but exposing for the shadows, creating a very bright picture.
Golden Hour
The "Golden Hour" refers to the first and last hour of sunlight -- right after sunrise and right before sunset. During this time, the light from the sun is very low in the sky, creating a warm light. Unlike the direct light that fills the rest of the day when the sun is more overhead, the light at this time of day creates long shadows that give depth and definition to your photos.
Backlight
Whether it is from the sun or from a studio light, backlight can be very effective when used correctly. Backlight creates a "rim" of light around your subject. Using a very small aperture on your lens and positioning your camera so the sun is just peaking around a tree or other object, you can create a starburst effect of the sun when you set your lens aperture to a high number, f16 or greater.
Rembrandt Lighting
Used in the studio and solely in portraiture photography, Rembrandt lighting uses a three-light setup that includes a main light on one side of the subject, a fill light and hair light set at half the power to the main light. You position the main light at a 45-degree angle to the subject and elevate the light that it is directed down toward your subject. When positioned correctly, a small triangle of light is created on the subject's cheek. This triangle is created by the subject's nose and is on the opposite side of the subject's face from where the main light is positioned.