The ArtStor database has a unique set of items that are useful in the discovery of images for music, dance, and other arts and themes besides the usual art history research. To get started, there is a guide available online that helps you learn quickly and easily how to use the database.
Detail from the Garden of Pleasures Mural, 1647, Interior Wall,
You can search in online catalogs for terms associated with images in books.
For example, use the terms "portrait" (often port for portrait in book catalogs)
Other examples: use "ill" for "illustrations" or "col" (for color)
Older books may use terms like "plate"
You can also look in the Table of Contents at the front of a book for "List of Illustrations"
For searching in ebooks or journal databases such as JSTOR, use terms like "image"
The problem with Google images:
1) images may not be available for use and can be in copyright
2) images are very often NOT labeled correctly. For example, if you search for a person, many images associated, but not that person can appear.
3) Can use google images to find a wikipedia image, which has usually been vetted.