Shannon Hale books in order
24 books in the catalogue, about 113 hours of reading in all; the shortest takes 2 hours and the longest 7 hours.
1 series and 21 standalone books in the catalogue.
Princess Academy
3 books
Standalone books
The Storybook of Legends 6.5 h 
The Goose Girl 7.0 h 
Enna Burning 6.0 h 
River Secrets 5.6 h 
Austenland 3.8 h 
Book of a Thousand Days 5.9 h 
Rapunzel's Revenge 2.6 h 
Forest Born 7.3 h 
A Wonderlandiful World 5.9 h 
Once Upon a Time 3.3 h 
Spirit Animals 4.4 h 
The Princess in Black 1.8 h 
The Unfairest of Them All 6.2 h 
The Princess in Black and the Perfect Princess Party 1.8 h 
The Princess in Black Takes a Vacation 1.8 h 
The Princess in Black and the Hungry Bunny Horde 1.8 h 
Best Friends 4.7 h 
Real Friends 4.1 h 
The Legend of Shadow High 6.2 h 
Diana, Princess of the Amazons 2.7 h 
Friends Forever 5.5 h