@Cheme2013. - I used the CERM manual the most, especially for steam tables, heat transfer, Thermo, combustion, fluids, etc - Crane 410 for fluids is also very helpful - Fogler textbook for reactions/kinetics (still had it from college four years ago) - NCEES practice exam was still very helpful - Perrys is good for misc. information if nothing else. I hadn't ever used it before I started studying but it is a wealth of information that can help answer some obscure questions (helped me on a couple). - Wankat for distillation/mass transfer I had one other textbook that was beneficial but I cannot recall the name of it. It was a "Basic Principles of Elementary Chemical Processes" type title and was also very helpful. Honestly, doing practice problems similar in difficulty and structure to the NCEES practice exam would be my best recommendation. The PPI problems are way more difficult than what you would see on the exam. I also work for an EPC design and construction firm, so I have had a lot of industry exposure and performed a lot of design calculations for fluids, distillation, heat transfer, process control, etc. in a short amount of time. That definitely helped the studying and being able to rely on intuition on a lot of problems.