In the Good Person of Szechuan, Shen Te, a prostitute, is hospitable to three gods. They reward her kindness by giving her a tobacco shop, which proves to be a gift and a test. The gods wants to see if Shen Te can remain a good person while trying to run a business and earn a profit. Shen Te is split by the urge to be good and succeed, so she invents a male cousin, Shui Ta, and disguises herself as him.
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.
You won't get any frills with GradeSaver -- just the content you expect. Their study guides include a full plot summary, themes and character analysis, study questions, and the e-text of the book. One hidden gem is their collection of literature essays, but you'll have to pay for it.