The subscription database called NoveList is a great source for book suggestions. Are you looking for an author like your favorite? Have you read the last book in a series and looking for a similar series to read? The database provides read-alikes for authors, titles and series. You can also browse by theme, genre and award winners.
Their link to Read-alikes provides information on how to start your search. You could also click on "Quick Links" and choose options from the drop down menu including Book Club Resources, Books to Movies and Grab and Go Book Lists.
Another subscription database useful for book recommendations is Books & Authors. This online resource has descriptions of thousands of recommended adult fiction titles from multiple genres (teen and children's titles, too!). It is useful if you want to know the sequence of a book series or if you are looking for authors who write in a similar genre or style to a favorite author.
Books & Authors also has a new feature called WHO WHAT WHERE WHEN that lets you browse by Character, Subject, Location and Time Period; it then gives you a visual representation of your matching books.