Search out online sites that focus on issues of diversity, race, ethnicity, sexual orientation, gender, disabilities, and other diverse specialties. Read publications, watch television/cable TV, listen to radio owned by or oriented toward diverse groups.
Contact diversity and/or race relations specialists. Check universities, institutes, diversity consulting firms, companies known for diversity efforts. Meet with diversity committees or diverse people in your own organization.
Contact organizations that represent diverse groups, i.e. Hispanic Chamber of Commerce, African-American Coalition, Asian-American Association, The Deaf Center. Your own company may have its own versions of these groups as well.