Harry is the poor tortured Hero. Thats why JKR likes throwing all these problems at him. But latley, he's loosing the whole 'hero' persona. At least, with PoA onwards he is developing his faults --> He's more human now that he was in CoS and PS. By the time you get to OotP, he has the attitude of a typical 15 year old, not some Saint. Still brave, but by no means perfect.
As for LotR, there are certainly similarities, but like Generator said, most fantasy books are built around the same storyline. And even with that in mind, there isn't that much thats really the same, not that I can see at least.