Linhsan-

The - Focus on the Family - website has book reviews of a lot of books. Those reviews tell you if there is any profanity or sexual nature in the books. It also tells about the religious beliefs within the book.

I use this site from time to time if I come across a book I think DD7 or DD9 might like, but I haven't read, don't have time to pre-read, or if I have read a book in the past and just can't recall if there is anything in it that I don't think we are ready for just yet.