In total, I feel that the article is well written.
Lead The lead appears to correctly bold/italicize the first line and the first sentence or two gives a good description of the subject of the article. The rest of the lead (which is of appropriate length) is clear and successfully gives a general idea of the complete subject without going into extreme detail, nor does it "tease" the reader. The infobox gives all of the information that the documentation for Template:Infobox book deems necessary (although it doesn't actually say that it's fiction...).
Layout Although I like most of the section headings, this article really needs a Further Reading or See Also section. Good job on the interlanguage links, though.
Word choice I don't see any words that introduce bias or are ambiguous. No words are repeated excessively. Some sentences do, however, organize their words in strange ways. I also notice several minor spelling and grammatical errors. One example: there is a confusion between "read" and "red" at the end of the Development and Promotion section. Since none of these errors change the intent of the sentences they're in so I don't think I should go into much more detail about that, but make note of it.
Fiction The article does a good job using secondary sources as well as staying in our universe. I like how the Plot section even goes "The Son of Neptune begins with..." The plot section is extremely detailed but stays to the point.
Lists I'm not really sure about this one. In regard to Major characters, the closest list type I can find on the policy is the Definition List, which would look weird. But, looking through other similar articles, House (TV series) (which was featured) uses a table... I suppose the current format is perfectly fine. The Camp Jupiter section appears to correctly use the "children" format.
a (references): b (citations to reliable sources): c (OR): The article appears to use mostly if not all outside resources, excluding the Plot section (I don't really see how it couldn't).
It is broad in its coverage.
a (major aspects): It looks to me like it does a good job of staying on topic but still answers all of the questions one would expect from such a page. b (focused): See a.
Fair representation without bias: In my opinion, the article appears to represent all associated parties fairly and without bias.
It is stable.
No edit wars, etc.: Well, I'm probably not the right person to ask about this, but looking through the edit history I don't see any real edit conflicts (besides vandalism, if course). So I'm just going to say I don't really have enough experience looking through edit histories to pick them out, and call this one unknown.
It is illustrated by images, where possible and appropriate.
I don't really see how it could use more images, since I don't believe the book was illustrated. I'm unsure whether a caption was necessary under the infobox picture (I can't find the relevant policy), but it would've been nice. The cover image appears to have been correctly tagged and licensed.
Overall:
Pass/Fail: In total, I'd say this is a well-written article and deserves GA status.
Comments Not sure about the "Camp Jupiter" section; it seems just to be some trivia from the book. Is there a universe page for the series this can be moved to? Also, most of the references need works/publishers. The "Promotion" info may be better merged with release, and the "Development" could probably include info from The Lost Hero article about why Riordan decided to continue from the first series, how it is different, etc. I haven't looked, but there may be some interviews about this books as well. The sentences: "It led to speculation that the book would explore the events surrounding Percy and his involvement with the Roman Camp for Roman demigods — Camp Jupiter. On May 26, 2011, Riordan released both the cover art and the first chapter of the book confirming such speculation." is referenced with this, which only confirms the date he revealed the cover and "sneak preview". It says nothing about fan speculation. I'm also going to disagree with the above reviewer; a "Furthur reading" or "See also" section is not necessary. Glimmer721talk01:52, 24 February 2012 (UTC)[reply]
I'll try to answer all your concerns here.
The Camp Jupiter Section- I completely agree. By the time you next see this I'll probably have an in-universe article for it and only have links to that page from this article.
Interviews- I'm sure some exist, and I'll look for them (I'm sure at least one exists though)
Fan Speculation- I didn't write that particular section and that ref is only intended for the cover art and sneak preview but I'll try my best to find a ref.
I'm not sure about creating a separate article for Camp Jupiter (Camp Half-Blood was merged with Percy Jackson & the Olympians, so you may want to do that). Don't work too hard in finding a ref for speculation; that is something that may not be reported in a reliable source, and might be best removed (unless you find one, of course!). Cheers, Glimmer721talk02:47, 24 February 2012 (UTC)[reply]
Ugg, I already made the in-universe article. If it gets merged with the Heroes of Olympus that's fine with me but it's there for now ;). --Kangaroopowah02:57, 24 February 2012 (UTC)[reply]
Update: I merged the speculation sentence with the followign one to make it more referencedish. ALso there is a link to an interview in the development section. Best, --Kangaroopowah03:10, 24 February 2012 (UTC)[reply]
I still think the speculation info info is best removed. Again, try expanding the development section with info and refs from The Lost Hero article, like why Riordan decided to continue with a second series and the new style of writing. Other comments:
The Lost Hero and The Mark of Athena need to be italicized in the lead.
"First person narration" is not the new style; Percy Jackson was first person, this is third-person with alternating points of view each chapter.
Think it's still on the NYT bestseller list; you can check out the website and report how many weeks it's been on as of this week.
See if you can find anymore reviews. The major ones like Publishers Weekly usually have to have a subscription (PW might be free, though), so I've heard libraries usually have access to those sites.
Thanks for the feedback. I finished the first, third and last pieces of feedback but I'm concerned about the POV in the book. I believe it is alternating first because there is no external narrator saying the story and it is all by the characters themselves. Is there a flaw in my logic? --Kangaroopowah20:48, 26 February 2012 (UTC)[reply]
First person uses first-person pronouns such as "I". The book alternates third-person limited omnicient, giving insight into one character for one chapter and so on. Glimmer721talk23:36, 26 February 2012 (UTC)[reply]