While it's relatively easy to find images on the web by, for example, searching Google, not all web sites provide accurate information about the images you may find or make presentation-worthy versions of those images available for free. A few sources to try with tips for using them wisely:
Books are also a good source of images. A few strategies for searching the catalog in a way that will help you target books containing images on your topic:
Found an image in a print book or magazine that you'd like to use in a PowerPoint or other digital presentation? The library complex has scanners in the Information Commons and Dwight Hall MEWS. You can get help at the Technology Help Desk in the Information Commons and from student consultants in the MEWS during staffed hours. Staff at both locations can also help you with Photoshop image editing software as well as PowerPoint.