The National Research Council's America's Climate Choices project has released a series of videos that provide an excellent brief overview of scientific understandings of climate change.
The videos describe both the lines of evidence and the history of the science that led to our current understandings of climate change.
The series of videos can be watched in separate segments, or as a single 26 minute long video. Here are the chapter titles linked to the videos:
The project has also produced a booklet of the same name. You can read the pamphlet online and download a pdf of Climate Change: Lines of Evidence here.