Place raw peanuts in the shell in a colander and rinse with cold water to remove dirt. Do not soak the peanuts. A quick rinse is all they need. Drain and pour on to a towel and then pat dry with another towel. The peanuts will still be a bit damp.
Preheat oven to 350 degrees.
Place raw peanuts, one layer deep in a shallow baking pan.
Sprinkle with about 1 - 2 teaspoons of salt.
Roast in a 350°F oven for 20 to 25 minutes for in-shell peanuts.
Remove from heat just short of doneness desired, as peanuts continue to cook as they cool.
I roasted them for about 20 minutes and then took them out of the oven. Cooking time depends on how roasted you like the peanuts.