The following link takes you to a site with great examples of how to cite images using Chicago Manual of style in your papers. You can also consult the Chicago Manual in sections 12.31 - 12.51 for directions on how to write captions and credit lines.
Common presentation tools for computer platforms are:
PowerPoint - PC and Mac
Keynote - Mac only
ARTstor Offline Image Viewer (OIV) - PC and Mac
There are several other ways to present images in the classroom depending on which OS and hardware you are using and what programs are available to you.
Presentations on iPad and iPad 2 +:
Keynote - The Keynote App will read not only presentations created in Keynote on your comptuer, but also PowerPoint presentations. As with most PC->Mac conversions animations will be lost, but it works.
PDF - You can export PowerPoint presentations as a PDF and present it with the PDF reader app of your choosing.
Image Files - You can also export your PowerPoint presentation as images. File formats suggested are .jpg, .gif., and .png.
From the web - You can also convert your PowerPoint to a movie and share via sites such as YouTube. You can also use a PowerPoint share site such as authorSTREAM.com or DocStoc.com.