Navigating the world of copyright and image use can be difficult, even for experts! The VRC recommends the following resources:

• The Visual Resources Association's Statement on Fair Use of Images for Teaching, Research, and Study
• The College Art Association's Code of Best Practices in Fair Use for the Visual Arts
• The Visual Resources Association's Intellectual Property Rights Committee has links to many resources about copyright and image use. For example, the Digital Image Rights Computator will help you determine the intellectual property status of a specific image. 
• Art Libraries Society of North America's Fair Use in the Visual Arts: Lesson Plans for Librarians

While not strictly about images, the VRC also recommends

• The American Library Association's Fair Use page
• The Documentary Filmmakers's Statement of Best Practices in Fair Use
• The Center for Media & Social Impact's Codes of Best Practices
• Thinking Through Fair Use, University of Minnesota Libraries

For guidelines for using images from Artstor, visit their Copyright and Image Use in the Artstor Digital Library guide. 

There are lots of great resources about and ways to cite images--always check with your instructor first. When using images in Artstor, try their citation generator to get started. Edit the generated citation as needed--while a great tool, this automatic feature cannot always account for the unique metadata present in each image record. For more information on how to cite images check out this page on the Art History guide.