A great way to start doing research on a new topic is by getting an overview or in-depth background information. One of the (many) great things about reference works (tertiary sources) in American Studies is that they are written by scholars in the field and often include references to relevant secondary (and primary) sources. Print reference sources are located in the Reference section, on the 1st Floor of the Library.
The Library has hundreds of reference books that provide authoritative background information on topics in American Studies. Here is a sampling:
Encyclopedia of American Studies
Encyclopedia of American Cultural and Intellectual History
Dictionary of American History
Encyclopedia of African American Culture and History by 
The Encyclopedia of New England by 
Gale Encyclopedia of Multicultural America by 
The Italian American Experience by 
Jewish-American History and Culture by 
The Encyclopedia of the Irish in America by 
The Asian American Encyclopedia by 
Encyclopedia of Southern Culture by 
Encyclopedia of the American West by 
Working Americans, 1880-1999 by 
Encyclopedia of American Social History by 
The Cambridge History of American Literature by 
The Greenwood Encyclopedia of Multiethnic American Literature by 
The Oxford Companion to African American Literature by 
Encyclopedia of Contemporary LGBTQ Literature of the United States by 
St. James Encyclopedia of Popular Culture by 
Beat Culture by 