I couldn't find a single bookstore while I was in Memphis, so I wound up buying "The Lightning Thief" from Wal-Mart.
It's entertaining. It's no Harry Potter, but the story is a little more exciting in most places. Percy comes off as a dumbass and I think the author developed his character solely from watching MTV and Nickelodeon. Some of the dialogue is awful in some places (especially Percy's first-person narrative) but the story is fun.
I may pick up the other two books tomorrow if this one turns out okay.