There is a website called "Atheism News", and this November they posted a video from the Center for Inquiry, which is run by the Council for Secular Humanism. In the video, founder Paul Kurtz explains, "What is Secular Humanism?"
The video lasts about an hour and makes for a good overview of the Secular Humanist approach to those not familiar with it. To see the video, click the link below.
What is Secular Humanism?