Flos Carmeli has a nice review of Amy Welborn's "Book of Saints". I recently bought this book for my niece. I hope she likes it.
I know someonewho wouldn't pick up the bible or CS Lewis or Chesterton or anything with the "taint" of religion, he would and did pick up a book on saints. The attraction, of course, is their idealism and uncompromising love for God as shown by their actions. That is so attractive in this world of political expediency and "reasonableness". The authenticity is what he thirsts for, and the saints had it.
But if we're honest I think there's also a gothic element in many saint's books that can make the stories intrinsically interesting to today's kids. By gothic, I mean some of the more purient martyr stories that involve violence - the flaying of the flesh or repeated attempts to kill, etc. Those stories will grab the interest of kids - as does the exhibition of saint's relics. I haven't read Amy's book yet, but I hope she hasn't "tamed down" the stories and removed the more estoteric, even weird stuff since that may attract the kids initially. As I recall, "Butler's Lives of Saints" didn't pull any punches. But what do I know? Amy taught school for years and is more hip to what kids want than me!