This is a video I found on YouTube. It is a really good and well done video explaining LiDAR and the uses of LiDAR. Please find a link below the video to the NEON notes site which indicates this is the first of many videos to come so you might want to bookmark the site. I have worked with the folks at NEON and they do some really cool stuff with LiDAR so check it out.
I will also post under the About LiDAR page so you will have reference to this site for future use
WiLDER LiDAR Blog 
A very informative primer to the world of LiDAR for the layperson.