High Dynamic Range Images and Environment

I have been doing research and to get good materials/textures/reflections most people set up world textures and High Dynamic Range Images. How do I do this I haven’t found anything too useful on it.

Google is your friend, i typed in HDRI lighting cycles and the first result was relevant – http://www.blendernerd.com/environmenthdr-lighting-in-cycles/

Environment texture for Blender internal

(Screenshot by Olson)

Thank you both for the help. I will look through those and mark this as solved if I can figure it out!