Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Mark's Standard Handbook for Mechanical Engineers

I have a slightly older copy and I have found that for the PE exam this is a good reference however, if you are doing something in the real world, the Machinery's Handbook is FAR better. This book gives good overviews of a huge variety of topics that any Mech Engr might need but not much depth. It is about as much information as a manager might want to know.