Ditto on Lucille Clifton. There's also
Rita Dove (who is a former Poet Laureate of the U.S.) and the late
Beah Richards. If you're interested in reading some poets from around the time of the Harlem Renaissance, there's
Angelina Weld Grimké and
Mae V. Cowdery. Oh,
Audre Lorde, though she was mostly known as an essayist, was also a noted poet.
Ntozake Shange has written poetry, and so has
Alice Walker (her book "Revolutionary Petunias" is a poetry collection).
Sapphire's a good (and prolific) poet as well. And finally, a triad of black Canadian poets:
Karina Vernon (who has a poem featured at blackvenus.net this month),
Mercedes Baines (her poetry is very sensual and sometimes funny) and
Joy Russell (who deals with biracial identity in her work).
Hope this helps!
Edited to add a link to the book
Shadowed Dreams - Women's Poetry of the Harlem Renaissance, which will be very helpful.