Copyright

An image you find on the Internet was taken or made by someone and that person should be given credit.
Because an image exists in a fixed form (unlike an idea), it is protected by copyright.
Images don't need a copyright symbol (a "c" inside a circle) to be protected by copyright.
Your best bet is to search for images the author has given permission for others to use (under a Creative Commons license) and to credit the author.

If you are using copyrighted images for your presentation, it can't hurt to put in a disclaimer statement like: "This educational [presentation, poster, slideshow, etc.] contains images protected by copyright law. When possible, images were used as permitted through Creative Commons licenses or available in the public domain."

Here are some sites to use when looking for images:

search Flickr's Creative Commons. Photographers here have specified how their images may be used.
search Wikimedia Commons, where again, photographers are identified and have specified how their images may be used
the Library of Congress' American Memory and Digital Collectionshttp://www.loc.gov/library/libarch-digital.html is a treasure trove of primary source materials--photographs, films, recordings, etc. Some--but not all--of the collection is in the public domain (not protected by copyright) because it belongs to the American people (Public Works projects) or is old enough to have fallen out of copyright. Works are clearly identified so that you have the information needed to cite it.
use Google's "Advanced Image Search." Under "Usage Rights" select "Only images labeled for reuse." Once you have found an image, click on "Website for this image" on the right sidebar so that you can find the source and author of this image should you need to cite it later.
"Finding and Using Public Domain Photographs"http://www.publicdomainsherpa.com/public-domain-photographs.html from Public Domain Sherpa

Here are some sites to help you document your sources:

Here's an online photograph citation example from the Library of Congress's site:

Last name, First name Middle initial. Title of photograph. Original date of photograph. Title of Online
Collection. Date of posting. Current location of original document. Database. Sponsoring organization. Day Month Year of access <electronic address>.

Example:

O'Sullivan, Timothy H. Incidents of the War. c1865. Selected Civil War Photographs from the Library of
Congress, 1861-1865. 12 Jan. 2000. American Memory. Lib. of Congress. 2 Aug. 2005
<http://memory.loc.gov/cgi-bin/query/r?ammem/cwar:@field(NUMBER+@band(cwp+4a40875))>.

Below are examples of how you can briefly credit an image source in your school work:

LIBRARY HOURS:

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(802) 482-7125

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Copyright