The National Museum of the American Indian is one awesome museum with buildings and activities in Washington DC and in New York City. Since this is one of my interest areas, I have been a member of the NMAI even before it opened the DC museum. I have only enjoyed the magazines and on-line material but friends who have visited said the museums are great, too. Here is the calendar of events for both New York City and Washington D.C.
National Museum of the American Indian