To create a spread, all you have to do is: 

1. Click on a book or create a new book
2. Click on "Add pages":
   
   
   
3. Select the images you want on that spread by clicking on "Images" (you can also add a text page):
   
4. Once you have uploaded your photo or photos, the spread will be saved automatically. 

Add 1-6 photos to a spread and include a title and text on the left page if you like.