What is an easy way to display images one after the other on a sign?

The easiest way to achieve this is to create a Group Animation in Creator:

Open Creator and make a new sign
Upload all your images into the Media Management
Drag and drop all the images you need onto the canvas (one on top of the other). Resize/position as necessary
Right click on a layer in the Layers Palette on the the right-hand side of the page
Select 'Add Group' from the list
Drag and drop all the image layers into the group
Right click on the group layer you have created and select 'Animate Group'
A pop-up will appear where you can enter in how long you would like each image to show for (in seconds)
Once done, click the publish button to save the sign