Primary and Secondary
Encyclopedias, books, journals, etc.
There are a number of different types of resources one can use
Primary Sources - first hand or contemporary accounts of an event written by someone who experienced or witnessed the event. These are often unpublished documents and can include diaries, letters, speeches, interviews, etc. They can include reports on events if they are close to the event and not historical accounts.
Secondary Sources - interpret primary sources. They are often published works including books and journal articles but could include radio and film documentaries. Secondary sources interpret, critique, analyze and assign value to the events in primary sources.
Primary Source - City of God by Augustine
Secondary Source - Levering, M. (2011). Linear and participatory history: Augustine's City of God. Journal Of Theological Interpretation, 5(2), 175-196.
Primary Source - Lincoln's Gettysburg address
Secondary Source - Schwartz, Barry. 1996. "Rereading the Gettysburg Address: Social Change and Collective Memory." Qualitative Sociology 19, no. 3: 395.
Encyclopedias - provide an overview of a topic or basic information. Sometimes bibliographies of recommended sources on a topic are listed in an encyclopedia article. There are many subject specific encyclopedias as well as general ones. Encyclopedias are a good place to look for background information or a place to begin when working with a topic that is unfamiliar.
Newspapers - report on what's happening day to day--nationally, regionally and locally. Newspapers do primary research talking to eye-witnesses and persons involved in an event. Some do in-depth primary research on a story.
You can search for newpaper articles in Newspaper Source Plus. Historic Newspapers can be searched using Early American Newspaper, 1829-1922, African American Newspapers, 1827-1997 as well as the Historic New York Times
Popular magazines - for the general public. They have lots of advertising and tend to be highly illustrated. Several databases index both popular and scholarly resources. Readers' Guide Retrospective: 1890-1982 (H.W. Wilson) provides access to historic resources in popular magazines.
Scholarly journals - for scholars to report their research. Written with other scholars in mind. The research done in scholarly journals is very specific and sometimes very technical. There are many databases indexing scholarly journals. Some are subject specific while others like Academic Search Complete and Academic OneFile are general and cover lots of topics.