The McGill Library Catalogue uses subject headings from the Library of Congress. These categorize books and other resources according to topic, and can be used effectively as search words for finding material.
The subject heading used for Black Canadians is Blacks -- Canada. Searching this term, instead of others such as "African Canadians," will yield better results since resources in this category will include as many relevant titles as possible regardless of the term used by the author of a particular book.
Blacks -- Canada can be further categorized according to subtopics. For example:
If a book is about a specific province or city in Canada, then searching those terms will yield more relevant results:
If you are looking for material on a specific group within the Black community, there will sometimes be more specific subject headings:
It is not necessary to know all the available subject headings in order to search. You can start with a keyword search using elements of the examples above. Then, look within the records of any books that seem useful to find out what categories the book is in and then select one in order to find others on the same topic: