When learning to code a new specialty, your best bet is to NOT code from a cheat sheet. The more you research and learn yourself, the better coder you'll become. Coding is not easy, and requires you to do your own research and learn to assign codes appropriately.
I suggest you make sure you have current CPT, ICD-9, ICD-10 and HCPCS books. Ask your billers to run a charge report, so you can see what kinds of codes the provider has been billing for in the past. Ask for access to the website for your provider's professional association. They often have coding help on their sites. Get a subscription to the CPT assistant. If your provider does surgeries, check them out on You Tube, so you can see what it is he's doing. Sit with your provider and learn about his work. Find out if there are any other neurosurgery coders in your area. Take them out to lunch and ask if you can pick their brain and ask questions. You can always ask questions on this web site, but make sure that the respondent can back up their answer with guidance.
Check your payer guidelines to see if there are any special coding rules. Research common diagnosis codes and learn about the disease process. Read the CCI edits pertinent to neurosurgery. See if AAPC has any webinars you could view. Get the E&M audit tool from your local contractor, and read up on both the 1995 and 1997 guidelines, to determine which set are more advantageous to your provider.
I will say, that my suggestions are not the easy way out. A cheat sheet may seem like a good idea, but one size does not fit all when it comes to coding. I strongly discourage them, and advise coders to look at each case individually and carefully so as to not make mistakes. Enjoy learning this new skill.