Composer-based research guides can provide excellent starting points for any project focused on the work of a particular composer. They inevitably include annotated bibliographies of key primary and secondary resources, lists of works, references to important editions, and much other useful information.
Search for research guides to scholarly works on composers using the following formula:
[composer's last name] AND bibliography
For example, to search OneSearch for research guides on Benjamin Britten
Thematic catalogs are fundamental resources for serious research on a composer's body of work, providing not only musical incipits to the works, but also basic information on dating and provenance, surviving manuscripts, early performances, publication history, modern location of sources, and much other key data.