This is a guide for The Tale of Despereaux that I have used with 6th-8th graders. It does NOT have an answer key, but it does include detailed questions for each chapter that check comprehension but focus mainly on theme, character, author's craft, and predictions.
This guide has really helped my students go back to the text during discussions because each question has a page number next to it (corresponding to the paperback version of the text). It also has a suggested schedule that is a little over 3 weeks--I print these out and have students use them as a bookmark. I hope your students find this guide as helpful as mine did!