Just for the record, I have read all the books multiple times and I understand that the movie won't follow the book completely.
But they could at least follow the story line a bit more.
So, the beginning of the movie starts out at camp. I actually didn't mind the very, very beginning of the movie. I thought it was fun. It all went downhill from there.
The next few scenes slightly follow the book in a way that it is good enough to pass.
Then you get to the oracle where Percy learns his destiny. THEY DIDN'T EVEN FOLLOW THE MYTHOLOGY! They said that Cronos swallowed all of his kids EXCEPT Zeus, Poseidon, and Hades. Then they chopped him up. Those who don't know, he swallows all of his kids except Zeus who is taken away until he's old enough to trick his father into throwing up all of his kids and they - depending on the version - castrate, or chop up their father.
They then proceeded that at the demigod's 20th birthday (I can't complain too much, Logan Lerman can't pass as a thirteen year old) he shall either save or destroy Olympus.
Setting out on the quest, to save Thalia's tree, with Annabeth, Tyson AND Grover, who we know is in Polyphemus' lair, stalling their marriage. Grover is kidnapped and sent to Polyphemus who we later see, slightly following the book, dressed as a woman, pretending to be a maid.
They don't know where Luke is, who is the one who captured Grover, so they go to see his Dad, Hermes, at the Demigod post office.
They learn he's on a boat, they leave, find the boat, and they're stuck. When they do escape, they go into the sea of monsters and get swallowed by the first monster they come by in the book. Meeting Clarisse down there. They escape together and finally get to an island.
In the book, Polyphemus lives on a nice island that has green grass and is completely healthy, thanks to the fleece. You've got the flesh-eating sheep and all that jazz.
In the movie, they get to the island that is an abandoned amusement park. They go down this roller coaster for a few seconds until they get stopped by rocks, which marks the entrance to Polyphemus' lair.
Fast forward, they have the fleece, and locked Polyphemus into he lair with a boulder. They meet Luke and his men, including Selena Beauregard (I might not have spelt that right) who practically saves the day in the fifth book, and they shoot Tyson who falls into a chasm.
Finally, they're tied up and Luke uses the fleece to revive Cronos. He succeeds and Cronos swallows Luke and Grover.
Percy's blade saves the day and they put Cronos back in the coffin. Grover is back and Luke is thrown into Polyphemus' cave where we assume he's eaten.
Annabeth is stabbed and she dies. Then is revived by the fleece. Tyson is back and they head back where the camp is waiting.
The rest makes sense, they go back to normal life, but alas, Thalia has been healed and is back.
I hope to god they don't make another movie. There isn't a way for them to make another one and still have the same outcome that they have in the book unless they do some crazy thing that barely passes for OK. I don't know what Rick Riordan was thinking when he helped - if he helped - with the making of this movie.
DO NOT SEE IT IF YOU HAVE READ THE BOOK. It's a waste of money and time.
Tingnan pa 
