Much of this advice is good for any state, not just North Carolina.
My first stop would be to the website for the particular state you are interested in. In this case
http://www.ncbels.org/
For other states you can find the board website listed at the
NCEES website.
From that site I recommend you download and read all the board rules, policies, and statutes. Usually the state specific test will be written to cover that material.
One thing North Carolina does differently than many other states is to test knowledge of Hydrology. We are licensed to perform drainage calculations
incidental to the design of a subdivision. (No water line or sewer extensions, just
incidental to the design of a subdivision. That means you need to brush up on your drainage calculations as well as the state specific material you will find on the website.
Hope that helps.
Larry P