To peel or shell shrimp, remove legs first. Using your fingers, open shell lengthwise down the belly of the shrimp. Starting at the head end, pull the shell away from the body. The tail can either be left intact or removed by gently pulling it off.
To devein, use a sharp knife to make a shallow cut down the back of the shrimp. Use the tip of the knife to pull out the dark vein running down the back. Thoroughly rinse under cold running water.
Deveining is optional. The black vein that usually runs along the outer curve is not harmful and has no flavor, but some people find it unappetizing.