This series is great for in-depth biographical information for some authors (not recommended for recent authors).
Try the following volumes:
Vol. 22: American Writers for Children 1900-1960.
Vol. 42: American Writers for Children Before 1900.
Vol. 61: American Writers for Children Since 1960: Poets, Illustrators, and Nonfiction Authors.
*to find entries in these volumes, look up your author/illustrator in the index by last name or use the online Literary Index.
You can do a keyword or subject search in OMNI for books about your author/illustrator (esp. for very popular authors).
Also, try a broader search, i.e. children's literature, children's poetry, young adult authors, etc.
Contains abstracts of over 5000 picture books for children, preschool to grade 3. Search over 900 keywords (topics, concepts, and skills) to locate books with storylines adaptable to your curriculum or program.
You can also try a Google search to find websites about your author. To filter out some of the junk, you can try searches like: