What’s Next?
A great site for readers to find information concerning adult fiction in series (two or more books linked by character, setting, etc.). Search by author, title or series to get the proper sequence of titles. The What’s Next™: Books in Series database was developed and is maintained by the Kent District (MI) Library

What’s Next? Teen Series and Sequels
The Bettendorf Public Library (Iowa) has created this site with a long list of books in series that have high appeal for teen readers, including fantasy books in series. Search by author or series name.

Juvenile Series and Sequels
The ‘Juvenile Series and Sequels’ database contains over 36,000 books in 4,900 series titles that are classified into three audiences: Juvenile Easy [JE] – for birth through 2nd grade readers; Juvenile [J] – for 2nd through 6th grade readers; Young Adult [YA] – for 6th through 12th grade readers. From the Mid-Continent (MO) Public Library.

LibraryLists’ Series and Sequels
A great collection of links.

FictFact
This site is “dedicated to helping you read fiction book series in order. Easily find out which book is next with a custom list based on your favorite series!