As far as advice goes...read, read, read. If your company has a policy manual start reading there, but don't stop. Know Medicare guidelines. For GI info (coding and more) checkout AGA.org
Google is a place to stimulate your thoughts but it is often not a reliable source. Remember, CPT, ICD-9,LCDs, etc. change all the time but the web keeps everything!
Know medicare guidelines. Then find out what other payers guidelines are
For scopes, understand screening vs. diagnostic. This is huge because a screening has a waived deductible. Most payers will not pay for an E/M with a screening scope most of the time. (dealing with a risk issue like a pt on blood thinners is an exception) Understand the multiple endoscopy rules.
Inpatient is a different beast. Too much to go into in a post. Go on your Local Medicare carrier's website and print out the inpatient manual and read, highlight, write info into your books, etc.
Congratulations and good luck!
Dee
CPC, CPCO, CPMA, CPCD