A video promo of your book is easier than you think. There are several free programs that will stitch pictures together. Even the newest iPhone has this feature. If you have Microsoft Office and know how to use Microsoft PowerPoint, it is easier still.
Make several slides with pictures to give a visual short synopsis of your story. Add commentary or dialogue to pique interest using textboxes or audio clips. Add music within the PowerPoint presentation, or wait until you create it as a video.
When you are finished, save a copy as a PowerPoint presentation so you can edit if you wish. Microsoft PowerPoint 2010/2013 provides a way to save your presentation as a video in only a couple clicks.
Save it again as a WMV (Windows Media Video). Convert the WMV to a movie with the built-in Windows DVD maker. PowerPoint 2013 allows you to skip this step and save directly as an MPEG-4 (movie), which is what is uploaded to the internet.
Create an free account with YouTube. Upload the video and reach the world-wide market. YouTube even provides royalty-free music to enhance your video.