I love the stories JK Rowling tells, but men, particularly dads, get the shaft in this series. Compare what Harry gets from his dad versus his mom. His dad gives him his hair, the Invisibility Cloak, his flying/Quidditch abilities, a godfather (although I think Sirius would have supported the Order and Harry anyway - heck Sirius might have lived without that connection), Snape's hatred. Even James' death doesn't do anything for Harry.
But Lily, the incomparable Lily, loved by all, gives him his eyes, the cure to Avada Kedavra, a family whose home protects him, a knack for Potions (the only time he does one with Snape or Snape's book, he gets an Exceeds Expectations), Slughorn's sympathy and memory, Snape's reluctant but necessary protection - this is good stuff.
Note also that Voldemort gets the heritage he prizes from his mother, and hates his father right down to his name. And Hermione is right pretty much 100% of the time (Half-Blood Prince is the only exception, and even that's kinda iffy). I'm not exactly boycotting the series because of this, but I wanted to point it out.
What If Harry ever told Dumbledore what was going on? Ya know, trust the guy who's made all these arrangements and proves his concern for Harry over and over? Depends on when it happens:
1) Sorcerer's Stone: Dumbledore learns that Hagrid was compromised, and just carries the stone in his own pocket - who's going to take it from him? Quirrell/Voldemort overplay their hand, and Dumbledore wins.
2) Chamber of Secrets: Dumbledore knows how to identify a basilisk, and since he knows about Moaning Myrtle's death, finds the secret plumbing passageway. Much less pain and chaos for all involved, and Gilderoy Lockhart doesn't end up a casualty.
3) Prisoner of Azkaban: Dumbledore might have recognized the Grim as Sirius (he knows everything that happens at Hogwarts), and is able to bring him and Pettigrew in with the truth. Voldemort's return is seriously delayed, although it could have gone worse in a post-Dumbledore world.
4) Goblet of Fire: Harry didn't really learn much before the ending, so no real answer here.
5) Order of the Phoenix: The Big One. Dumbledore easily could have handled Occlumency, and even if it had been difficult for Harry, it seems like it would have been better than Snape's lessons, and certainly better than the Ministry debacle. Also, Dumbledore probably would have tossed Umbridge to the centaurs sooner if he saw Harry's hand.
6) Half-Blood Prince: They finally had good communication. I suppose Harry could have told him about the Potions book, but I doubt that would have come up.
7) Deathly Hallows: *sniff* sadly irrelevant, although I do think Harry should've worked his way into the Headmaster's office sooner to have a chat.