The call number for Black women activists is E185.96 or 323.092396. Browsing the SSHEL Stacks or Main Stacks in this range could help you find sources.
Print resources are an excellent place to start your research. These books will provide some basic biographical information about the figures you're researching, as well as references to more complete biographies. These are all located in the SSHEL reference collection. If you need help finding any of them, just ask at the reference desk!