Nurse Auditor/coder

Hello. I'm not quite sure if this is the correct place for this but here it is...

I'm interested in a position as a Nurse Auditor. Some of these positions require coding certification and some require "familiarity" with CMS guidelines and ICD-9 codes.

What at is the best way to "familiarize" yourself with CMS guidelines and coding? Is it really worth it to become a certified coder? I'm not sure exactly what type of experience these companies are looking for when it comes to this. I've worked in an acute care setting for 7 years and have worked closely with case management and am aware of what differentiates an inpatient vs. observation stay and what qualifies a patient for either. I'm aware of the 2 midnight rule and other basic CMS stuff. Is this enough?

Long post short:

1) should I obtain coding certification for this type of position even if it's not required? Is it that useful and does it make me that much more valuable as a potential employee?

2) how do I familiarize myself with CMS guidelines?

thank you!!!