The Lightning Thief by Rick Riordan
Twelve-year-old Percy Jackson is a trouble magnet. He suffers from both dyslexia and ADHD and is about to be kicked out of his sixth school in as many years. He's not a bad kid, though, and doesn't intentionally cause problems. He's just always getting blamed for all the inexplicable things that happen around him.
When Percy discovers that he's a half god and half human and joins Camp Half-Blood, things start beginning to make sense. Now his biggest problem should be figuring out who his father is--Hermes? Zeus? Poseidon? Hades?--except that Zeus' lightning bolt has been stolen and he's the prime suspect. There's only way to prove his innocence, and advert war between the gods: Percy is sent on a quest (with only a satyr and a twelve-year-old daughter of Athena as help-meets) to find the lightning bolt.
The Lightning Thief is the first book in Rick Riordan's Percy Jackson and the Olympians series. I really enjoyed it and am looking forward to reading the other books in the series.
I liked how Riordan used switched things up by making things that are usually considered negative (dyslexia and ADHD) into indicators of inhuman gifts (I expect that if kids who suffer for one or both of these issues come across this series, it might help them feel a little bit better about themselves). I also appreciated how fully Greek mythology was incorporated into the story. The novel isn't perfect and there are a few aspects of the plot that don't quite add up, but overall I think The Lightning Thief is a very promising beginning to a new series.