I run a self-improvement oriented community. I continuously read books, some of them quite famous, and provide a summary along with textual quotations from each of the books reviewed.
Now here's the thing:
I do charge for access to this and there is no other content in the site aside from the reviews of all these books for whom I, obviously, haven't acquired an explicit license to reproduce them.
I do not know if what I'm doing falls under a fair use doctrine.
The content of the review usually contains no more than 4 or 5 sentences which are quoted verbatim from the book. Aside from that is pretty much "what the book is all about" in my own words.