Let me begin by saying that fresh shrimp means they were caught the night before. My son and I am getting ready to buy around 90 pounds or so for $2.50/pound. The couple I am buying from go shrimping the night before and sell the shrimp the next day. They are generally sold with the heads on and we will "head" the shrimp ourselves. There will be a later post on that process. The heads will account for about 1/3 of the weight so we should end up with about 60 pounds of headed shrimp. They will be a medium size, about 30 count. That means there are about 30 shrimp per pound. This chart is from http://www.finecooking.com/ and may help with choosing the size of the shrimp you want.
We had cooked some shrimp seasoned with Old Bay and had some left over. This is what I used for my shrimp salad.
First I needed to peel the shrimp. If you have never done this just know that you need to be careful of the sharp point just over the back fins.
Next use a sharp knife to cut down the back of the shrimp to devein it. BTW, this has nothing to do with a vein but that is what it looks like. The shrimp's stomach is actually located in the head area and is removed when the shrimp is headed. The intestine runs down the back of the shrimp and may need to be cleaned out. This is what is referred to as deveining. If you can see it you need to remove it. It will look like a black thread. If it is not visible it is empty and you can leave it.
Now chop them up! I had a heaping cup of diced shrimp today.
To the shrimp I added about 3 tablespoons Duke's mayonnaise, 2 tablespoons finely chopped onion, 1/2 stalk finely chopped celery, salt, and pepper. I usually add a little Old Bay but since these were previously seasoned with it I left it out this time. I do recommend using Duke's mayonnaise instead of other brands.
We like this served with saltine crackers. For a different twist you could add a bit of dill weed or some sweet pickle cubes.