When you find a good book, look around the shelves in that area for more. You are guaranteed to find something browsing you would miss keyword searching the catalog.
Explore tables of contents and indexes in books that catch your eye.
Speak the catalog's language - use Subject Heading vocabulary in your keyword searches. Click on Subject Heading links at the bottom of a catalog record to browse the collection for more materials in that subject. Subject Headings use a controlled vocabulary determined by the Library of Congress. Use specific subject heading language in your keyword searches to find primary sources.
These keywords are Library of Congress Subject Heading vocabulary indicating primary sources:
sources, letters, interviews, speeches, personal narratives, diaries, correspondence, sermons, notebooks, sketches, description and travel, treaties, pamphlets, biography (includes memoirs), newspapers, periodicals, pictorial works, art, architecture, portraits, caricatures and cartoons, cookery, decorative arts, furniture, material culture, guide books, maps, fiction, poetry, periodicals, newspapers, bibliography, early works to 1800
example search: (united states women) AND (sources or correspondence)
Search the Vassar Library Catalog:
This is one research technique, but not a perfect system. Many wonderful sources at Vassar do not have Subject Headings indicating they are primary sources.