A primary source is a first-hand account of something.
You don't have to look online for primary sources--many can be found in the Academic Course Reserves behind the library desk. These books are stored there so that you can easily find primary and secondary sources on your topic. Images in books of art, architecture, sculpture, or writing, can be used as primary sources. Don't forget about these easily accessible and valuable resources!
Below are some Databases that contain primary source information for ancient history.
From the Princeton Commons