Short stories aimed at children, contributed by site users, that can be downloaded/printed off and read to kids at bedtime. Stories can be rated by users, so that you can search by rating, posted date etc. The site would have an animal look and feel, but aimed at kids. The site would be quite a niche market, so you have good targeted advertising and once it's up and running you could charge a small fee to become a members and access the stories.
Great idea: A site where you have coloring books even though its over, I still wanna share some ideas