Here are the official sites of the religions featured in the workshop: Seventh-day Adventist Church; The Church of Christ, Scientist; The Church of Jesus Christ of Latter-day Saints; The Baha'i Faith; Worldwide Association of Jehovah's Witnesses
Other sites you might want to read concerning LDS are Role of Women in Mormonism, Current LDS Beliefs about Homosexuality, and The Mormon Pioneer Trail, which is a very good, detailed, factual (and lengthy) site.
Religious Tolerance.org has a very good Overview of Christian Science.
Jehovah's Witnesses are known for the publication of The Watchtower. Now you can read them online, as well as find answer to questions about what Witnesses believe.
The Most Segregated Hour in America is not the MLK interview; but, rather, an article on a diversity blog focused on spiritual life, January 2009. Other resources on multicultural congregations are Embracing Diversity: Leadership in Multicultural Congregations by Charles R. Foster (Herndon, VA: The Alban Institute, 1997), The Power of Stories by Jacqueline Lewis (Nashville: Abingdon Press, 2008), and D.J. Chuang has a blog with many multiethnic church resources. Be aware that most of these resources come from a Christian perspective. The UUA has a list of multicultural resources, too.