JStor is an excellent source for Art History papers as it has academic articles that date back to the 19th century. Be cautious of articles that are book reviews--these are not sources for your paper, but can lead you to excellent sources.
Access to full text periodicals-- contemporary academic journals, magazines, and newspapers and historical newspapers (New York Times, Los Angeles Times, Washington Post, and Wall Street Journal). Proquest also includes books in your search results.
QuestiaSchool provides online access to thousands of full-text books, academic and popular articles, and reference works. This is a great place to search for almost every research project. Everyone has a personal Questia login that is your school email address (firstname.lastname_XX@sfuhs.org) and the password: sfuhs.