Primary sources are the raw materials of historical research - they are the documents or artifacts closest to the topic of investigation. Often they are created during the time period which is being studied (correspondence, diaries, newspapers, government documents, art) but they can also be produced later by eyewitnesses or participants (memoirs, oral histories). You may find primary sources in their original format (usually in an archive) or reproduced in a variety of ways: books, microfilm, digital, etc.. This definition is taken from the Primary Sources Research Guide.
Finding Primary Documents in the Addlestone Catalog: Searching the Discover Service will access many primary documents to which we have online access. Using the search term "new france" is a good start. Under "Refine Results" limiting the "Resource Type to "Archival Material/Manuscripts" will directly access specific documents (as digital images) online. However, keep in mind that many - if not most primary documents - concerning the New France era were written in French (who knew?) and may not be useful to those not versed in that language. Also, the documents consist of images of the original, handwritten letters and may be difficult to read in any case. SEE example here.
Using Monograph (Book) collections of primary documents: Many primary documents have been published as collections in books or contain such collections or primary documents. A way to help you find such sources under the "Limit Your Results" is to choose "Sources" under the "Subject" facet. Other terms to use are correspondence, archival resources, archives, diaries, manuscripts, notebooks, or pamphlets.
These terms are Library of Congress subject heading subdivisions in the source record. The details for using these and other terms can be found on the MIT Research Guide: Finding Primary Sources: Library of Congress Subject Headings
Primary Documents in Bibliographies / Reference lists: The best place to start looking for primary sources are in secondary sources (books and articles) written about the subject you are researching. Academic authors must use primary documents when they write books and articles (just like you do). The primary documents they use must be referenced (documented) in their writing (just like you do). In effect you have a ready made bibliography of primary documents in every academic secondary source you find. Thus, a great place to seek primary documents is in the reference section of a book or article on a subject.
The looking in the reference list / bibliography of the secondary books on the history of New France in this guide is a great place to start. Other collections of primary documents concerning the history of New France are listed here.