Here is a few
http://autodeskmep.wordpress.com/
http://resources.autodesk.com/adsk/servlet/AutoCAD-MEP/tutorials.htm
http://resources.autodesk.com/adsk/servlet/Revit-MEP/webcast_archives.html <<<< they have some older AMEP Screencasts mixed with Revit MEP
http://cd.cadlearning.com/ <<<< these are not free but they are more in depth and if you search AUGI you can save some coin.