The Voyage of the Dawn Treader is the story of Lucy and Edmund Pevensie and their cousin, Eustace. It follows their return to the land of Narnia and their journey aboard the titular Dawn Treader, a ship under the command of Caspian, a Narnian prince. The ship conveys the cousins from island to island at the edge of the world. Along the way they experience many adventures, from dragon-infested isles to the doldrums of the golden sea.
Boasting the largest collection of book summaries, BookRags is the best option for titles you can't find elsewhere. They offer all of the basics (quotes, chapter summary, characters, historical context, literary criticism) but also walk through a few major topics that recur throughout the book, which can be particularly useful for essay writing.
If you're bored by traditional book notes, try Shmoop! They write their summaries in an approachable, entertaining style. Their comprehensive offering includes chapter by chapter summaries, themes, quotes, character analysis, study quizzes, and even flash cards and infographics.