Histograms offer powerful information to take and edit better photographs. They can be used to check for under/over exposure in the camera. They are incredibly helpful in setting the white/highlight/shadow/black/contrast in Lightroom or curves/levels in Photoshop to make images that look AMAZING.
In this quick video, I briefly explain what a histogram and demonstrate a simple way you can use the information to adjust brightness and contrast in Photoshop.