Harry Potter and the Chamber of Secrets
If Hermione is the brains and Harry is the soul, Ron Weasley is the heart of the Harry Potter series. He is generous, loyal, kind, and a great friend to Harry. When Vernon Dursley is keeping Harry a prisoner in his own room to keep him from Hogwarts, Ron comes with a flying car to rescue Harry. When Harry is hearing voices in the Hogwarts hallways talking about killing, Ron does his best to reassure Harry. Even though Ron is terrified of spiders, he still willingly follows Harry into the Forbidden Forest on the trail of the Acromantula Aragog (a huge, man-eating spider) to find out what is waiting for them in the Chamber of Secrets.
Besides being a loyal best friend to Harry, Ron's primary role in Book 2 is to have a large family. No, seriously: It's in Book 2 that Harry first encounters the Burrow, the Weasley household. He thinks it's "the best house he's ever been in" (3.183). Harry has grown up isolated from the wizarding world and from all the things Ron takes for granted: parents, brothers, and sisters. When Harry sees the Weasleys – the first wizarding family he's ever visited – it's like everything he's ever wanted in life. Luckily, Ron does have a sister…but more on that in the later books.
Of course, while Ron's close-knit family life seems warm and delightful when we first see it, we do know that there are problems with being a Weasley. The Weasleys are relatively poor, and Mr. Weasley works in one of the least-respected offices of the Ministry of Magic. Because he loves Muggles and our inventions, he works in the Misuse of Muggle Artifacts Office. Yet anti-Muggle prejudice leads Lucius Malfoy and people like him to think that Mr. Weasley is a fool who "[disgraces] the name of wizard" (5.176). Lucius Malfoy's disdain for the Weasley family and their poverty trickles down to his son, who often mocks Ron for his shabby clothes and low social status.
The Weasleys' poverty has a material effect on Ron's life in Chamber of Secrets. When he and Harry drive Mr. Weasley's flying car into the Whomping Willow, the crash snaps Ron's wand. As a result, for the rest of the year he can't do any spells without getting them wrong or hitting himself. He manages to curse himself with a slug spitting spell thanks to that broken wand. But he's worried, about telling his parents, getting in trouble, and then asking them to replace the wand. So he just suffers in silence. Yet, thanks to Ron's broken wand, Professor Lockhart manages to Obliviate himself permanently. Without Ron's poor family and broken wand, Professor Lockhart might still be at Hogwarts, so we actually owe the Weasley family situation a lot for saving us from that fate.