Summary
The story is about Percy Jackson: a demigod, son of Poseidon, Greek god of the sea. When the tree that creates a magical border around the demigod training camp is poisoned, Percy has to go on a quest to sail to the Bermuda Triangle and search for the Golden Fleece. Soon he discovers that the tree is poisoned by Luke, who wants the Golden Fleece to resurrect the titan Kronos. In the end, Percy reaches the island with the Fleece on it and defeats the Cyclops that protects it. Luke tries to steal the Fleece from Percy but luckily he has already sent his friend to take it back to camp and heal the tree.

Compare two characters of the book
Percy Jackson:
Percy wants to do the good thing: get the Golden Fleece to heal the magical tree of Camp Halfblood. If he doesn’t, the place will be overrun with monsters in no time, and the camp is like a home to him. Percy has to try to stop Luke from resurrecting Kronos, or Kronos will rule again and change the world as we know it. For Percy, his friends are the most important thing in the world. So important he would risk everything for them, even die for them, and that is also his fatal flaw (all demigods have one).

Luke Castellan:
Luke is angry at all gods of Olympus, and he tries to resurrect Kronos (the father of the gods) to take revenge on them. His purpose is to steal the Golden Fleece so it can heal Kronos. It is important to him to take revenge on his father, Hermes (god of travelers and thieves), and the other gods, because he thinks that they don’t care about their children.

Percy and Luke are nothing alike. Only when Luke was younger he was nice and more loyal to his friends like Percy, when he was still in Camp Halfblood. Now Luke is selfish, uncaring, and hateful, while Percy is everything except selfish. Although Percy is sometimes impulsive and doesn’t always think things good trough, he isn’t a bad person, and Luke is.

Special moments in the book
The book is written pretty hilarious. You can read the main characters thoughts and Percy has really funny thoughts. It is going to be hard to not write it all down, because if I do there will be 200 pages or something. I have written a few quotes to show what I mean. This is a piece from the book where Percy and his friend Annabeth were climbing to get to the cave of the Cyclops. This is what he told:

“We only came close to dying six or seven times, which I thought was pretty good. Once, I lost my grip and found myself dangling by one hand from a ledge fifty feet above the rocky surf. But I found another handhold and kept climbing. A minute later Annabeth hit a slippery patch of moss and her foot slipped. Fortunately, she found something else to put it against. Unfortunately, that something was my face.
"Sorry," she murmured.
"S'okay," I grunted, though I'd never really wanted to know what Annabeth's sneaker tasted like.”

When Percy and Annabeth were sailing towards the Cyclops’s island, they came past Circe’s island. Circe (the goddess of magic) hates men and likes to turn all that enter her island into guinea pigs (in the original story from the Greek mythology she turned men into pigs, but they were too big and too hard to keep, she explained). Unfortunately, Percy enters the island with Annabeth and is turned into a guinea pig. But Hermes had given Annabeth a sort of magical multi vitamins, that turned Percy back human.

“Before I could figure out how to apologize for being such an idiot, Annabeth tackled me with a hug, then pulled away just as quickly. "I'm glad you're not a guinea pig," she said.
"Me, too." I hoped my face wasn't as red as it felt.”

When Percy came back at Camp Halfblood, he saw that a lot had changed there, because there was a different camp leader with different rules. Here he describes that feeling.

“Ever come home and found your room messed up? Like some helpful person (hi, Mom) has tried to "clean" it, and suddenly you can't find anything? And even if nothing is missing, you get that creepy feeling like somebody's been looking through your private stuff and dusting everything with lemon furniture polish?”

After Percy finished his quest and got back safe at Camp Halfblood, he meets Hermes again. The first time they met, Hermes asked Percy to talk sense into Luke, about the gods being not that bad and that he shouldn’t be mad. After the whole quest, Hermes asked Percy about Luke, if Luke still wanted to take revenge on the gods.

“You weren't able to talk sense into him?" Hermes said.
“Well, we kind of tried to kill each other in a duel to the death," I told him.
“I see. You tried the diplomatic approach.”

I can’t really name the funniest moment in the book because there are so much, but I like the way the writer, Rick Riordan, makes you laugh even in the titles of the chapters. The title of chapter one, for example, is: My best friend shops for a wedding dress. Percy’s best friend is Grover, a satyr (a half-goat). The rest of the book is just as funny.

 I do know what the most exciting moment of Percy Jackson and the Sea of Monsters was. That was when Percy was on Luke’s boat and Luke almost killed him in a sword fight. But then a group of centaurs, ‘The Party Ponies’, came to help him out. That was also the part I most remember. And the moment I liked the least was when everyone realized that Tyson, a young Cyclops, was the half-brother of Percy (they have the same father, but Tyson’s mother was a nymph, not a human) and some demigods at camp were bullying Percy for that. Percy was first really popular for what he did in the first book (Percy Jackson and the Lightning Thief) and because he was son of Poseidon, one of the ‘Big Three’: Zeus, Poseidon and Hades. After everyone knew about Tyson, that wasn’t anymore.