The Lightning Thief by Rick Riordan is the first book in the Percy and the Olympian Series. Percy (short for Perseus, of course) Jackson, age 12, is dyslexic, has ADHD, and has been kicked out of more schools than you'd care to count. He's never met his father, and his mother has married a real terror, but she loves Percy very much and tries to take care of him. Percy has almost made it all the way through the year at his boarding school--the first time he has spent so long at any school. Of course, it can't last, and Percy gets kicked out after a series of strange happenings. His mother decides it is finally time to do what his father wanted and take him to summer camp, but not just any camp--Camp Half-Blood. Percy soon discovers that his father is one of the Greek gods and that gods and satyrs and dryads and all of the other mythical creatures are not myths at all. A war is about to break out between Poseidon and Zeus, and Percy must go on a quest and find a way to stop the war.
The book is fast-paced and full of fun mythological allusions. I love mythology; I took a whole elective on it in high school, in addition to the myths I was exposed to in my Latin and English classes, so I found this a really fun read. I think it will appeal to Harry Potter fans as well.