The accessible, if slightly underwhelming, site maintained by the official Jackson estate.
This page provides a thoughtful overview of Jackson's career. She was inducted for "Early Influence," and the page notes that gospel and spiritual music played a key role in inspiring more secular rock and R&B styles.
This report from February 2010 provides a brief audio biography of Jackson.
This humorous interview with the Chicago radio legend includes several stories about Mahalia Jackson, a long-time friend and collaborator of Terkel's. She once saved Terkel from losing a job, and another time she got Terkel an interview with MLK, Jr.