Series: PERCY JACKSON AND THE OLYMPIANS, by Rick Riordan.

Hero of The Lighting Thief, the teenaged demigod Percy (his father is the god Poseidon)  is a fascinating, classic hero in a set of tales that are as much fun as anything I've read in a long time.  All the readers in our family, from 9 to mid-70's, enjoy these tales that blend modern teenagers with the mythological gods of old.  Now 7 books long, the Percy Jackson series is well written, high-energy, page-turning adventure that keeps kids reading.  Highly recommended.