In addition to these sites below, try an extension/add-on for your browser. I like TWP - Translate Web Pages in Firefox.
Search the CLIO Catalog to find primary sources by adding keywords to your search, or look for them in the Subject - Genre filter. Here are some examples:
CLIO is the library catalog for the Columbia Library System (including Barnard Library, but excluding Teachers College and some information from the Law Library). In CLIO you can find books and media materials, search for different kinds of databases, and find articles within those databases as well.