How does culturally diverse families ( immigrants and refugees) impact the community?

First, "does" is a singular verb. "families" is plural. The verb and object should match. Families do, not does. For your question, read, read, read:

http://www.google.com/search?sourceid=navclient&ie=UTF-8&rlz=1T4VRHB_enUS648US649&q=immigration+impact