Take a shrimp into your hand and break off the head.
1 pound Shrimp
With your fingers, open up the shell, starting from the inner stomach/leg area where the shell is the thinnest. Take off the shell with the legs.
Decide if you want to keep the tail on or not, it's only needed if you want to use the shrimp as a dipper. The tail should be removed if you plan on sauteeing your shrimp or cooking them in a sauce or curry. Simply pull off the tail or break off.
With a small pointy knife (aka paring knife), lightly cut into the shrimp back along the dark vein. From top till down.
Take out the shrimp vein and discard.
Repeat the process with all the other shrimp.
Rinse the shrimp and remove excess water.
Use them up or store them in batches. Keep them in zip lock bags, that way you can freeze and thaw them as needed.