Peel the potatoes and rinse with cold water. You can leave it in cold water for a while to remove the excess starch.
On a high heat, add salt to the potatoes and bring to a boil about 15-20 minutes(depends on the size of the potatoes) or until the potatoes are soft enough for a fork to go through it.
Drain the water, and reduce lower the heat and let the liquid in the pot evaporate. Mash the potatoes.
Over a low heat warm milk and butter, until the butter melts completely. Add the mixture slowly to the potatoes and continue to mash, combine and season with salt and pepper.
Notes: You can melt the butter and milk together or if you don't want to go through that process, use soft butter (cut it up) and warm milk. Add milk slowly until the potato is creamy then add butter.