The slogan "The social network to discover the best children's books." might be used a tag line (optional, foresee both options with and without tagline).
Brand essence: inspiring children’s reading
Brand personality: knowledge, fun, passion about reading, honest, warm
Emotional benefits of Boolino: joy of reading, united shared passion (parents-kids)
Functional benefits of Boolino: helping parents to foster reading habits, recommendation of best and most adequate books at any moment, information sharing through social network and blog