The study of history is based largely on two things -- primary resources and historians' interpretations
Primary resources are an essential part of the study of history. They are the basic evidence for any historical argument. Moreover, they are as close as you can come to the actual event(s) you are researching. However, they must be examined with caution. First-hand accounts often exhibit some kind of misunderstanding or distortion. Therefore, usually more than one primary source is used in comparison with others.
Newspapers are a particularly useful kind of primary source. They can provide first hand, chronological accounts of events. They can also provide a sense of social values and popular culture of the time period. For some topics, particularly local history, newspapers may be your only supply of primary source materials. Moody Library has access to 2 historical newspapers, the New York Times and the Chicago Tribune. These online sources go back to the beginning of the publication of that newspaper, and continue to a recent date.
Reference books are an extremely useful first step in the study of history. They give directions on the research and writing of history, general overviews of historical topics, and/or information on how to find historical materials. You can use reference books to generate paper topics, to develop keywords, ideas and concepts related to your topic, and to find selected book and articles to get you started in your research.
Some books in the library are collections of primary resources. Generally, though, books are secondary sources, i.e. interpretations of historical events by experts in the field. These secondary sources are as essential as primary sources for the study of history builds on the work of previous and contemporary historians.
Journal articles are also secondary sources of information. They are much shorter than books, however, and so tend to focus on much more narrow and specific topics. For example, a book might cover the military history of the Civil War while a journal article might be about one specific kind of weapon used in one particular battle.
Indexes and databases give information about where to find materials. Databases are mainly full-text resources and provide the articles as well as the citations. Indexes provide only citations which tell you where to go to find the article or books they list.
That noble dream : the "objectivity question" and the American historical profession / by 
The Craft of Research by