I saw the movie last February and it convinced me and my sister to read Rick Riordan's books. The only other novels that I enjoyed reading was the Harry Potter series. I thought that Percy Jackson should be another series of fantasy novels that should be fun to read.

Synopsis:
Percy is what you call a demigod: child of a god and a mortal. His father is the sea god himself, Poseidon, so some of his powers are rubbed off on Percy. It's about his adventures with his friends: fellow demigods, a satyr, a cyclops for a half-brother, and a mortal.
Each of the books (except for Titan's Curse which happened on winter) starts every summer at Camp Half-Blood, the summer camp for demigods, then they go to a quest given by the Oracle of Delphi itself. Along their quest, they encounter Greek mythology monsters, and the gods themselves. All these as the titan Kronos plans and executes his revenge for the gods; and Percy is the one destined to decide if the era of the gods continues or if the titans regain all that was once theirs.

Top:
Annabeth Chase (Daughter of Athena), Percy Jackson (Son of Poseidon), Grover Underwood (Satyr)
Bottom:
Noco di Angelo (Son of *Spoiler*), Tyson (Cyclops), Rachel Elizabeth Dare (Mortal)
Review:
It's written in first person, on Percy's point of view. Each of Percy's adventures are all based on individual prophecies so we get the idea of what would happen as the story goes.
His adventures include trips and battles on epic locations such as the Underworld and the Labyrinth; and smartly placed locations of Ancient Greek places on American soil. From Mount Tamalpais (Mt. Othrys), to Mount St. Helen's (Mt. Etna), to the Bermuda Triangle (The Sea of Monsters), to the Empire State building (Mount Olympus).
It's like the present-day America clashing with Greek mythology.
It has a lot action between demigods, monsters, gods and titans themselves. We have demigods using swords, bow and arrows, spears, and shields; with the main characters having a special unique weapon that has magical properties. They can also use powers and abilities that they inherit from their god parent. We get a glimpse of both the gods' and the titans' powers and their classic and famous weapons like Zeus's lightning bolt, and Kronos's scythe.
Overall: Classic battles of epic proportions. The books may look intense, but they were still very easy to read, in a sense that the words were phrased in a very simple way. If you have the time, you can finish each book in a day or two. Every plot of each of the five books finish in a way that keeps the readers satisfied. It's a really great series.