Jon Snow is the base-born son of Eddard Stark. He was raised at Winterfell, and treated like any of the other children by his father. However, Catelyn Stark resented him as he was a constant reminder of her husband's infidelity.
As he nears adulthood, Jon makes the decision to join the Night's Watch where the circumstances of his birth would not matter.
Samwell Tarly a steward of the Night's Watch. He is very intelligent, but is often teased for being overweight. His father Lord Randyll Tarly, seeing him as no fit heir, forced him to join the Nights Watch.