"Primary sources are original records created at the time historical events occurred or well after events in the form of memoirs and oral histories." Some examples of primary sources might be: serials (journals, magazines, etc.), government documents, memoirs, artifacts, photos, and even works of art.
Primary documents fall into 3 categories:
-- from The University of Nevada, Reno
For a closer look at different types of primary sources, see Yale University's detailed discussion.