While there are many approaches to library and archives research, here are some suggestions for beginning your research on W.E.B. Du Bois (and by extension, any and all related topics and individuals).
1) Consult the Five College Catalog using Du Bois's name as either an author (if you are looking for works by him) or as subject (if you are looking for books about him).
2) If you need to go beyond the resources of the Five Colleges for books, films, etc., then consult the WorldCat database for materials by and/or about him as per no. 1 above. This is a particularly useful tool for discovering archival materials that are beyond the Five College collections.
There are numerous databases which index articles on Du Bois and related topics. Many of those databases also link directly to the articles themselves or indirectly via links to other databases or interlibrary loan.
Among the most important sources for articles are:
1) Academic Search Premier: Citations, abstracts and full text articles from scholarly and general-interest periodicals relating to social sciences, humanities, education, physical, and biological sciences.
2) America: History and Life: Citation information and abstracts for journal articles, dissertations and book reviews on United States and Canadian history, from over 2,000 journals published since 1964.
3) Black Studies Center: Combines several resources for research and teaching in Black Studies: Schomburg Studies on the Black Experience, International Index to Black Periodicals (IIBP), The Chicago Defender, and the Black Literature Index. IIBP provided indexing and abstracting of 150 African, American and Caribbean periodicals, with full text of forty core journals. The Chicago Defender was at one point the most widely-read black newspaper in the country, with more than two thirds of its readership based outside Chicago.
4) Black Thought and Culture: Monographs, essays, articles, speeches, and interviews written by leaders within the black community from the earliest times to 1975.
5) Dissertations and Theses: Citations and abstracts of doctoral and some maters theses, mostly completed in colleges and universities of the United States and Canada. Full text access to UMass dissertations.
6) Ethnic NewsWatch: Full-text collection of newspapers, magazines and journals of the contemporary (20th and 21st century) ethnic, minority and native press. Search can be focussed by choosing "AFRICAN AMERICAN/ CARIBBEAN/ AFRICAN" in ethnic group of publication.
7) Historical Abstracts: Citations and abstracts for articles and book reviews from over 2,000 journals published since 1954, on all aspects of world history from 1450 to present (excluding the Untied States and Canada). Publications are in over 50 languages; article titles and abstracts are included in English translation.
8) International Political Science Abstracts: Citations and abstracts from approximately 900 journals and yearbooks in the fields of political science, international relations, public administration, and public law.
9) Modern Language Association International Bibliography: Citations and abstracts to journal articles, books, book chapters and dissertations in the fields of literature, literary theory, linguistics and folklore.
10) Sociological Abstracts: Citation information and abstract to journal articles and books in sociology and related disciplines (anthropology, economics, education, medicine, philosophy, social psychology, etc.) from 2,500 journals in 30 languages. The database also includes abstracts of sociological conference papers, relevant dissertation listings, and citations to book reviews.