Goodreads- This site is a great place to go to look for books related to what you know you already liked, book reviews, popular books, genre-specific, topic-specific...the world's largest site for book recommendations.
Children's Literary Awards - An intro to the Newbery, Coretta Scott King, Schneider Family, and Stonewall Awards.
Book Resources - Info on various genres and recommended titles in each, including narrative nonfiction and materials for kids, middle grade, and young adults.
Jennifer LaGarde's Padlet - Books to help readers tackle tough topics including gun violence, immigration, sexual assault, addiction, mental illness, racism, poverty, and disabilities. There's some amazing selections here and it's a digital work in progress.
NPR Book Concierge - Annual collection of the best books of the year. People can filter by multiple categories at a time, including such diverse options as Eye-Opening Reads, For Music Lovers, For History Lovers, Comics & Graphic Novels, Kids' Books, and Young Adult. Visually browse options by book cover and link to reviews, book excerpts, author interviews, and why the staffer picked it as a Best Book of the Year. Note - this site includes books for early readers on up to adults.