It is Just a search engine, kids use it all the time and it is apprpritae for ages:6-older beacause it is like bing yahoo, or msn so let your kids go on any search eingene they want.
I wish I had this resource back in high school and college writing papers. So tedious it was spending money on copy machines, micro fiche, going to the library, buying cliff notes, etc....really helps expedite the process. Amazon tries to compete with their resources and reviews on books. the eBay great solution dot com will help with free reviews, resources, tips.