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Well, I just used the official book and a test on android (https://play.google.com/store/apps/details?id=com.pocketprep.ceh). Skillset frustrates me and many questions there are not from the test. You should read and understand the Introduction Chapter very carefully. There are many questions on policies, terms, etc. I also wrote down the main points from Footprinting, Scanning and Enumeration. That helped me remember them better. There were very few crypto questions, no mobile or cloud questions. Main things for me would be: knowing what the main tools of the trade are (NESSUS, etc), what shellshock and heartbleed are, the terms, nmap flags (many questions like "what does this command do?" or "how do you perform a xmas scan?", phases of ethical hacking, what kinds of firewalls, IPSs and IDSs there are, wireless attacks definitely. And read through the viruses, sometimes it's not entirely logical. There was a question about the types.