Images abound! There are many free online collections, of which several are listed below. Many books in the library contain images that you can scan and use in your paper or presentation. Oftentimes, Google Images will quickly yield the image you need, but always remember to limit to your search to "free to use or share" in the Advanced Search settings for "usage rights" and trace the image back to its source in order to give credit to its creator.
Advanced Search allows you to limit your search results by:
To determine if a book you find in Discover (SFU's library catalog) contains illustrations, click on the title to view the book's record. Open the "Description" and look for mention of illustrations or color plates in the "Physical Description" field, as in the example below: