I finished the Lightning Thief!!! Here is a brief summary of what happenned.
So Percy is at Camp Half-Blood and he finds out that his dad is Poseidon. He also discovers that his dad is being blamed for the theft of Zeus's symbol of power, the master bolt. Percy sets off on a quest to prove his father's innocence and to find the master bolt. On the way he encounters many monsters and after finally reaching the underworld (they beleive that Hades has the bolt), they discover that Hades's helm of darkness is missing and that he thinks that Percy took the bolt and his helm. Percy disovers that the bolt is indeed in his possession and that Ares tricked him into taking it. They escape the underworld and find out that Ares took the helm of darkness. Percy battles Ares, defeats him, and returns the helm. He then go to Olympus and returns the master bolt. He returns to camp-half and is betrayed by Luke who tries to kill him.