I think it's hard. Harder than reading, anyway. BUT these ladies (Ellen Potter and Anne Mazer) make it seem like fun! I heard about this book at the BYU Symposium for Young Readers back in July. I've been singing the praises of the book to all my teacher friends ever since. I think with teacher guidance this book could be useful really in third grade through middle school. Budding writers working independently ... maybe just a tad older at fourth or fifth grade.
Don't miss out on the blog. Their teacher kit has some premade, ready to download/print "I Dare You" posters. The dares were some of my favorite parts of the book. Well, those and Matt Phelan's illustrations.