"Distro" is short for distributor - these organizations and companies sell zines on behalf of the creator. They are a useful resource for purchasing zines, and maybe you'll find a distro to submit your zine to as well.
Accessing ARTstor Free Images:
ARTstor provides free use of images for noncommercial, scholarly and academic purposes through the Image for Academic Publishing (IAP) initiative.
In order to find images that are free to use add the keyword "IAP" to your search.
For example, if you are looking for images of works created by Leonardo Da Vinci you would search "Da Vinci IAP"
You can find more information about the IAP initiative here.
Google Image Search is quick and easy to use, and more often than not you can find the image you're looking for without too much effort. However, because it searches for image names and contextual words on the basis of popularity, results tend to be uneven.
How to Find Free or Public Domain Images:
1. Do an initial search in the search box, similar to how you would search Google.
2. Under the search box on the results page, locate the Search Tools option.
3. When you click Search Tools and additional line of options will appear.
4. In order to narrow your search to images that you can reuse, click Usage Rights, which will display a drop down of options.
5. You can only choose one option at a time, but each option will define a specific circumstance for reuse, choose the one that is appropriate to your activity.
Flickr is an online photo management and sharing software which hosts the personal collections of its users and public archives. While many of the images are high-resolution and unaltered the quality will vary depending on the creator. You do not have to create an account to use flickr, just look for the search box in the top right hand corner to start.
Flickr is also home to "The Commons," which includes the collections of over 45 institutions, including NASA, the Imperial War Museum, and the New York Public Library.
Finding Free and Public Domain Images:
1. Do a search for images that you would like to find in the search box.
2. Beneath the black heading bar there is an option to choose the license type, using the License drop down.
3. To narrow your results to only those that you can reuse, choose the Creative Commons option.
With the Creative Commons option you can also choose if you would like to find images that can be reused for commercial purposes or that can be modified.
4. You can check the Copyright restrictions on images, by clicking on an image and locating the copyright symbols to the bottom right of the image. The Some rights reserved link will take you to an explanation of how you may use the image.
The same search techniques will work in both flickr and The Commons to find free and public domain images.
Determining the Copyright for images from the internet can be tricky. Here are some resources to learn more about the topic.