As noted in a prior post Autodesk and DLT Solutions have teamed to offer LiDAR for Dummies Special Edition. This free online reference was written by James Young who works for Aerometric an aerial mapping firm based in Wisconsin.
James has done a great job with this text, but I would caution readers it is not really for dummies. There is a lot of really valuable technical information on airborne LiDAR from an operations perspective.
Definitely worth a read.