I installed the PhotoGuide but cannot find the pictures.
The photos in the PhotoGuide are in the main page, but not every entry has photos. You can go to Set Tool Display (Display menu) and set the thumbnails to Medium or Large, then you can easily see them in the articles, and click on them to get the full picture. Be sure to save this as the default for this tool.
The neat way to access the tool is to make it the default tool opened when double-clicking on a name in the Atlas. You can do this in Set Map Display (Display menu) or Preferences > Map Tab Display, and make it the default for new map windows.