When I lived up North, I worked for the Philadelphia School District for a while. We had MLK day off.
There were a lot of questions of what to do with the time. Some folks parked themselves in a mall and shopped, others took the attitude that it was a day to go out and help their neighbors and do something positive for society.
One year I took the time and found the audio track for Martin Luther King's speeches. While I can't post them all here, I can post a link to his last speech. The next day he was assassinated.
If you have never taken the time to listen to the man speak, you should. He truly was an amazing speaker. The topics are just as pertinent today as they were back when he was still alive.
Regardless of your views it is certainly worth the time.