The books I found most useful for the Controls exam were:
Instrument Engineers Handbook vol 1&2
ISA Stantards 5.1 - 5.5
ISA Control Systems Engineering Exam Reference Manual: A Practical Study Guide
Fisher Control Valve Handbook
Crane Flow of Fluids
I also took about 10 other books but...
Control systems - I passed! I felt good about it after the morning session but not so sure after the afternoon session. The results came on Thursday and my wife had to read them to me over the phone since I was working in Florida. I live in the Kingsport area.
