Agent Kristin Nelson has an interesting series of blogs (starting April 25 through May 6th) on creating the pitch paragraph or paragraphs about your book for a query letter.
She shows how to discover what the plot catalyst is in your novel, then how to build your pitch around that catalyst using plot, character, background, or a combination of these elements.
Her blog is located here: http://pubrants.blogspot.com/
We both believe that the catalyst moment is the most important focus for creating either a pitch or a blurb for your book, but my method differs a bit. To read my article on creating a blurb or a query pitch, go to marilynnbyerly.com and read my articles on writing blurbs and query letters.