What type of images?
For More information page images you can set the maximum number on Preferences > Extra Fields.
Other than that all the other screens are limited to the images that are on the configuration for that type of page, i.e. Pages have Banner Graphic, Link Graphic, Back ground graphic, similar settings for registration, shopping cart etc.
You can also include the url to image in most text fields so you could put them in Text 1, Text 2, Text 3 on pages, or in the global Header, Footer etc.