Looking for an image online that you can legally and safely use? Google now makes it easier to find one.
Run your search at the Google Images page, or just use Google's default search page and then filter the results by image. Click on the Search tools menu and then select the drop down menu for Usage Rights.
That menu offers five choices: Not filtered by license, Labeled for reuse, Labeled for
commercial reuse, Labeled for reuse with modification, and Labeled for commercial reuse with modification.
Select the option you wish to use, and the page refreshes to include only those images.
The images are typically ones licensed by Creative Commons or GNU Free Documentation, or are items in the public domain. The "labeled for reuse" option allows you to use the image for non-commercial purposes as specified in the license. The "labeled for commercial reuse" lets you use the image commercially. The "reuse with modification" option grants you the ability to alter the image.
A Google help page describes the various licensing and usage options.