Scholastic Book Wizard - This site recommends books based on reading level, grade, and interest. This is a great tool because it leads to reading recommendations that are subject appropriate, not just reading level appropriate. It is important to find a high interest books for older children that are not reading at grade level, as well as finding challenging books with subject matter that is appropriate for younger children reading above grade level.

Children's Library - Free 3600 books from 60 countries in 48 languages online -

What should I read next? - Enter a book you like and the site will analyze the database of readers favorite books and make suggestions based on who else read this book.

Big Universe - Read, Write, and Buy Children's books online

Book Adventure - Help me find a book. There are also other parts of this site that are enjoyable.