Book + Trailer: Seraphina, by Rachel Hartman

Four decades of peace have done little to ease the mistrust between humans and dragons in the kingdom of Goredd. Folding themselves into human shape, dragons attend court as ambassadors, and lend their rational, mathematical minds to universities as scholars and teachers. As the treaty's anniversary draws near, however, tensions are high.
(From the YouTube description)

Book + Trailer: The Long Earth, by Terry Pratchett

Starring:

• Sir Terry Pratchett (@terryandrob) - multi-award-winning author of over 50 bestselling novels and co-author of The Long Earth
• Neil Gaiman (@neilhimself) - Author 
• Stephen Baxter -- multi-award-winning author of many bestselling SF novels and co-author of The Long Earth
• Rob Wilkins - Sir Terry's assistant and stenographer
• Peter James - Bestselling author and film producer
• Tony Robinson - Actor, Comedian, Historian, TV Presenter and long time reader of Sir Terry Pratchett's audio books.
• J. Spoon - Sir Terry Pratchett fan. 
• Philippa Dickenson - Random House Children's Publishers UK
• Michael Logan - Author of Apocalypse Cow and joint winner of the Inaugural Terry Pratchett Anywhere But Here, Anywhen But Now Prize. 
• Robert Llewellyn - Actor, Presenter and Writer
• Bernard Pearson - Discworld Emporium
• Tina Andreadis - Harper Collins Publishers USA
• Brianne Halverson - Harper Collins Publishers USA
• Gavin Hilzbrich - Transworld Publishers UK
• Ade Hill - SFX Magazine
• David Logan - Author of Half-Sick of Shadows and joint winner of the Inaugural Terry Pratchett Anywhere But Here, Anywhen But Now Prize
• Danielle Plafsky - Harper Collins Publishers USA
• Mark Sainsbury - Random House Publishers New Zealand
• Michael Edwards - Sir Terry Pratchett fan
• Andy Hancock - Sir Terry Pratchett fan
• Dave Golder - SFX Magazine
• Rob Wilkins - Sir Terry's assistant and stenographer
• Suzanne Bridson - Transworld Publishers UK
• Reb Voyce - Discworld Emporium
• Sir Terry Pratchett - multi-award-winning author of over 50 bestselling novels and co-author of The Long Earth
• Stephanie Selah - Harper Collins Publishers USA
• Myke Cole - Author of the Shadow Ops Series (Ace)
• Mark Ferguson - Harper Collins Publishers USA
• Simon Taylor - Transworld Publishers UK
• Stephen Baxter - multi-award-winning author of many bestselling SF novels and co-author of The Long Earth
• Michael Turner - Sir Terry Pratchett fan
• Jen Brehl - Harper Collins Publishers USA
• Kathy O'Brien - Transworld Publishers UK
• Katie O'Callaghan - Harper Collins Publishers USA
• Marianne Velmans - Transworld Publishers UK
• Esi Sogah - Harper Collins Publishers USA
• Kai Mathur - Sir Terry Pratchett fan
• Ian Mitchell - Sir Terry Pratchett fan
• Lynsey Dalladay - Transworld Publishers UK
• The Guards
• Derek Taylor - Sir Terry Pratchett fan
• Larry Finlay - Transworld Publishers UK
• Tom Hopke - Harper Collins Publishers USA
• Henry Vines - Transworld Publishers UK
• Tess Henderson - Transworld Publishers UK
• Emily Krump - Harper Collins Publishers USA
• Mike Spradlin - New York Times bestselling author of It's Beginning to Look a Lot Like Zombies! (William Morrow)
• Jannine Saunders - Transworld Publishers UK
• Ruth Johnson - Transworld Publishers UK
• Sacha Allen - Sir Terry Pratchett fan
• The Guards
• Dave Bradley - SFX Magazine
• Pam Jaffee - Harper Collins Publishers USA
• Jonathan Paterson - Transworld Publishers UK
• Sir Terry Pratchett - multi-award-winning author of over 50 bestselling novels and co-author of The Long Earth

http://www.terrypratchett.co.uk/

1916: the Western Front. Private Percy Blakeney wakes up. He is lying on fresh spring grass. He can hear birdsong, and the wind in the leaves in the trees. Where have the mud, blood and blasted landscape of No Man's Land gone? 

2015: Madison, Wisconsin. Cop Monica Jansson is exploring the burned-out home of a reclusive - some said mad, others dangerous - scientist when she finds a curious gadget - a box containing some wiring, a three-way switch and a...potato. It is the prototype of an invention that will change the way Mankind views his world for ever. 

And that's an understatement if ever there was one...

The Long Earth is the first novel in an exciting new collaboration between the creator of Discworld Terry Pratchett and the acclaimed SF writer Stephen Baxter
(From the YouTube description)

Book + Trailer: Rebel Bookseller, by Andrew Laties

(@AndyLaties) via @GalleyCat:
Barnes Kong is on a rampage! The simian chain bookstore monster could go on stomping on independent bookstores and kidnapping dead authors forever, but the fearsome Amazilla has other plans: he wants in on the action. As the two battle with their laser e-readers, they destroy every public institution in sight. Can the Rebel Bookseller save the day, rescue Emily Dickinson and bring back a community of books?
Credits: Andy Laties, Nere Kapiteni, Rebecca Migdal, John Landino, GLOVE, Jessica Higgins, Denis Luzuriaga, Mary Averill, Matt Waugh, Eric Blitz
(From the YouTube description)

Book + Trailer: The Year of the Gadfly, by Jennifer Miller

(@propjen)
Iris Dupont is a teenage reporter who communes with the ghost of Edward R. Murrow. Jonah Kaplan is a failed microbiologist-turned biology teacher who is haunted by the ghosts of his past. Each embarks on a private investigation to uncover a secret society in their remote New England town. As Iris and Jonah's paths start to intersect, they are drawn into the darker corners of their town, their school, and their own minds. Glamour Magazine calls THE YEAR OF THE GADFLY "Part Dead Poet's Society, party Heathers. Entirely addictive." www.byjennifermiller.com
(From the YouTube description)