According to the America's Most Literate Cities study , not so very -- try "tied for 38th" with Louisville. The study ranks the largest cities on "six key indicators of literacy: newspaper circulation, number of bookstores, library resources, periodical publishing...
Over on Neighborsgo.com, Plano's Doug Valentine has written about his creation of a video he entered in the Gale/Librareo contest ... and won. I can't embed the video, but if you've ever checked out a book from a school library...