How to add photos to a Concrete Gallery

First upload your photos (from your computer) using File Manager and creating them as a "set".
1. Sign In to your website.
2. Click on Dashboard, then File Manager.
3. To the right of the Upload button select More.  Upload multiple files (Add Files) if you have more than 1 image.
4. Once the files are selected from your computer choose Start Uploads.
5. A window will pop up when complete.  Choose Assign File Sets then Add to New Set and finally choose Update.
File Manager will now contain the photos you wish to use on your site organized into "Sets".  "Sets" are different galleries to use.
Second add a gallery link on your website.
1. While still signed into your website, choose Sitemap.
2. If you going to add a new gallery to your website, click on Photobook and choose Visit.  
3. Choose Edit Page and under "Photo Galleries" add another link to the new photo gallery.
4. Choose Exit Edit Mode and Publish Your Edits.
Finally, you'll need to assign the photo set to the gallery link.
1. While still signed into your website, choose Sitemap.
2. Next to "Photobook" click the plus sign (+).
3. Click on the link for the new gallery and choose Visit then Edit Page.
4. Click on Add To Main, scroll down to choose Galleria Image Gallery.
5. Under Type, select Pictures from File Set.  Select the correct File Set then Add.
6. Publish Your Edits and Sign Out of the website.