On the Beach is a post-apocalyptic novel by Nevil Shute written in 1957 about people in Australia waiting to die of radiation poisoning after the Northern Hemisphere has been destroyed by nuclear war. The Australian survivors receive a Morse code signal from the United States and send out a submarine commanded by Captain Towers to find survivors. They arrive in Washington and find that the signal is not coming from a human after all. They return to Australia, where many families have already committed suicide.
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.
The most popular website for book notes. SparkNotes was created by students for students, and their summaries are accessible and extremely well-written. Besides the usual plot overview, chapter summaries, and character analysis, SparkNotes differentiates itself with a section discussing themes, motifs, and symbols.
Their book summaries aren't as good as other providers, but PinkMonkey often has interesting insights that aren't mentioned elsewhere on the Internet. For example, they go over literary elements (like setting, conflict, and mood), compare and contrast, and symbolism/motifs. It's a good site if you want to find a unique fact or angle that other students don't know about.