Once upon a time, everyone peeled potatoes before cooking.
Then, a new idea started circulating: most of the nutrients in potatoes are in the skin. So I began eating potatoes cooked in the skins.
Recently, I have learned that some really unhealthy chemicals are used in potato fields. So if you are eating the skins, you may be consuming small amounts of these chemicals.
That's when we switched to organic potatoes, so we can eat the skins and get the nutrients, without the chemicals. (Ann grows organic potatoes in her garden.)
In my opinion, If you can't get organic potatoes, you should peel your potatoes.
Here's a link to my wife's blog InspiredGardening.com that will show you how to peel potatoes easily.
Eat smart and stay healthy.
There are 37 pesticide residues found by the USDA Pesticide Data Program in potatoes. Source: http://www.whatsonmyfood.org/food.jsp?food=PO