Portrait Lighting Setup poster to be helpful. It contains 24 different portrait lighting setups using a variety of lighting gear and lighting patterns. Click the image to see it up large. Also check out some of the further reading.
Exposure Lock (AE-L Button) is the abbreviation stands for Automatic Exposure Lock. It is useful using automatic and semi-automatic shooting modes. Where has this information been all my photographing life? So freaking helpful it's not even funny.