Atticus is more of an instructor than a daddy to his children. He doesn't play football with Jem or have little tea parties with Scout. He wants to teach them to be decent people by his definition: "Fine folks were people who did the best they could with what they had," rather than by Alexandra's definition that a person's name makes him/her better or worse. He instills these values by example. He defends a black man even at the cost of his reputation...which, by the way, is NOT tarnished as many people say it will be. He treats Arthur Radley like a neighbor, not like a ghost.
Scout changes from a hot-tempered, self-absorbed child into a reflective, caring young lady. She changes from "Well, after all, he is just a Negro," to "I knew that if I got my dress dirty, Calpurnia would have to wash it again before Sunday." She changes from nosey about Boo Radley to considerate of his needs, when she seats him in shadow on the porch and makes sure he is ushering her like a lady when they walk home.
Jem changes from a know-it-all who thinks Maycomb is the best to a young man who has seen racism and doesn't like it. He really struggles with the outcome of the trial, in contrast to Scout who isn't really affected by Tom's death.