Obviously, this is late since you've probably already taken the exam, but for the people who haven't taken it, it might be helpful. CHES wasn't hard, but I definitely don't think it wasn't an easy exam, especially for people who might have been out of the classroom for a while. I found that a lot of the concepts were familiar to me because I have a bunch of books that I happened to go through before the exam and I'm still in school.
I didn't even actually really study for the exam, mostly because I didn't know where to start. I bought the "Competency-Based Framework for Health Ed. Specialists-2010" suggested on the website. Eugh. Didn't help me one bit and I'm annoyed I wasted my $$! I would say your best bet for studying if you've been out the classroom for sometime would be to refresh yourself by going through a few of the books listed as resources for CHES exam prep. Even then, there will probably be some question topics you have never seen. In those cases, eliminate the outlandish answers at least down to 2 choices and guess!!