Fantastic Fiction is a great resource for looking up all the books by an author. Fantastic Fiction also can tell you all of the books in a series, in order, and will suggest other books that are similar to the author/titles you are looking at.
Literature Map is a resource that helps you find authors similar to an author that you like. Simply type in an authors name and it will create a map of similar authors. The authors closest to the center are going to be the most similar.
Common Sense Media is a great tool for parents! You can search for apps, books, and movies/TV shows and see the rating for children. Reviews from other users are included that describe if there is any profanity, violence, etc.