Complete help can be found here.

Item reordering: Items are reordered by dragging the first column (№) up or down.
URL variants: URL should look like the following:
- https://web.site.address/folder/subfolders/image.jpg
- http://web.site.address/folder/subfolders/image.jpg
- https://web.site.address/folder/subfolders/pagename.html
- http://web.site.address/folder/subfolders/pagename.php
- dir://folder/subfolder
dir is a directory under your blog root folder, uploads folder or the folder where Galdget is installed.

Groups:
- Items with group 0 are displayed on all galleries, use group 0 for, e.g. logo or trademark pictures.
- You can put more than one group for an item, separated by comma.
- Each gallery (widget or shortcode) displays items from one group, plus group 0 items.
Save button: When you save this list, it is immediately available to the galleries of your blog. Please don't save incorrect, intermediate or temporary variants, use export and import instead.
Export and Import: You always export the whole list into a file. On import you may choose to append the file contents to the existing list, or to delete existing list before the import.

You may want to visit the Galdget pages and see the detailed instructions, restaurant menu demo, animations showcase.

When you finish setting up your URL list, the next step is either to set up a Galdget widget (Appearance / Widgets) or create a shortcode in a page or a post.

You may also want to take a look at the paid version [Galdget plus+] and restaurant menu demo with frames and list of frames.