Legal Question in Intellectual Property in Missouri

The answer to this question is fact-specific, so you would need a lawyer to review your product. Summaries of the books may be a fair use depending upon the quantity and quality of the amounts taken from the underlying work, although if you plan to sell the calendars that commercial use would weigh against a fair use determination.

Reproducing the entirety of a book cover may be more problematic. Unless the design of the cover is in the public domain, you would be reproducing the entirety of the work. Often the cover art is protected under a different copyright than the book, and the author/publisher had to get permission to use the image and/or other materials on the cover.