Here are some Getting Started guides and basic fundamentals of the game:
NationStates Frequently Asked Questions
This page, written by Max Barry, will give you an excellent overview of what you have just gotten yourself into.
One Stop Rules Shop
A mega-thread created by the NationStates Mods. New players almost always think that anything goes in terms of what you can say and what you can do.
After all, it is a political game. However, that couldn't be further from the truth. These are the game's rules, mostly covering behavior.
Getting Help/Reporting Infractions
There will be times when you see someone doing something that is offensive or in direct violation of the game rules.
This is where you can file a report with the Mods. When filing a report, remember that the Mods are volunteers. Be brief and polite.
Every region can add tags to their description that can be used to inform about the type of region it is. The Tag Cloud is an easy way to look up what regions match what tags.
The Legal Stuff