I have never suffered from a learning disability, or any kind of hyperactivity disorder (unless you count Restless Leg Syndrome, which I am dead convinced that I have), but that doesn't mean I've never daydreamed about finding out I'm the child of a god. Huh. That sounded a little bit psycho. Still, I think you know what I mean. In that sense the first installment in the Percy Jackson series is classic kid-wish-fufillment fantasy. Percy's life with his loving mom, not-so-loving step-dad and ADHD and dyslexia problems is tough, and when he finds out his father is Poseidon it doesn't get any easier. It does, however, become...more. (I don't think this is a spoiler, because this is the set up for the ENTIRE SERIES) Percy lives his life with pizazz, once he settles down to his destiny of fighting monsters in between difficult terms at school. Isn't that what most of us want, even as adults? On another level, seeing a kid with ADHD and dyslexia get to be the hero of a story has to be heartening for kids struggling with it every day.
I am prepared to concede that I'm a sucker for anything where the gods appear in mortal guise (Dating waaay back to Hercules and Xena. Admit it, you watched them too...) but I also really like these books for themselves. The first one in particular may feel a little like a high quality Harry Potter knock off, but by the time I reached the end I wasn't connecting Percy with Harry at all, despite their similarities. I cared about Percy, Annabeth, and Grover for themselves, not just as stand ins for Harry, Hermione and Ron. The way the Greek mythology is continuously slipped into both the plot and modern culture is really clever. And in the end, although Harry and Percy have loads in common with one another, they don't really feel the same. Harry is an earnest young man, trying to save the world, because he's the only one who can, by making the best choices. Percy feels more like a borderline juvenile delinquent yelling at adults to shape up and act like adults (or in this case, gods), because he can't clean up this mess all by himself. Anyway, I would recommend giving it a try- worst case scenario, it won't take very long to read.