How should I wash the potatoes before baking them?
For baking potatoes


Don't just wash them, scrub them.  Otherwise you're eating dirt.  No, that's not a joke.  Potatoes grow in dirt, and are usually sold coated with dirt.  Yes, really.
Either salt them and wrap them in tin-foil, or simply bake them on a 
bed of salt.  Dessication of the skin is important. 
You'll probably      want to bake them longer and higher than most
recipes say.  I find       425F for 1 1/2 hours is optimal (and 2
hours is fine).  That results in skin which is dry, crispy, and slightly caramelized, while this inside still is fluffy (albeit, according to some, overcooked).