Re: copyright: It was made clear that music used in the making of booktrailers should be of free use and links to sites were provided:
CHOOSE YOUR MUSIC CAREFULLY!: Copyright is an issue when it comes to using someone else's songs in your trailer. Freesound: https://freesound.org, Jamendo: https://www.jamendo.com/es/welcome
and the same for images when creating the Genial.ly presentations:
Choose your images carefully, make sure they are royalty-free!
Sites where you can find free pictures:
http://search.creativecommons.org
Flickr’s Creative Commons Free Pictures: https://www.flickr.com/groups/creative_commons-free_pictures
Gratisography: http://gratisography.com
morgueFile: http://www.morguefile.com/archive
Pics4Learning: http://pics.tech4learning.com
Photo5: http://photos5.com
Pixabay: https://pixabay.com/es
Or tcredit who the author of the image is
or go to google images,
look for your image and check by image rights of us by clicking on tools.