What tutorials are you trying to follow... I believe all the files should be here:
http://usa.autodesk.com/adsk/servlet/item?siteID=123112&id=11273335
Refer to the Revit MEP Imperial and Metric Datasets as appropriate.
Martin Schmid
Product Line Manager
Mechanical Detailing and Electrical Design
Architecture, Engineering, and Construction
Autodesk, Inc.