Well, that's certainly a very general statement!
First, the actual NS Game itself is simple enough. You are given issues, and you decide on those issues. The way in which you decide on those issues will alter your nation, change it, etc.
Now, as to the forums here, which in my opinion is the far better part, some things that might interest you:
The Bazaar: The heart of the Taijitan economy, it is here that all goods and services being offered by sale by our residents can be purchased. If you're an entrepreneuring individual yourself, you can set up your own store as well in the hope of earning a few extra Tai.
The Delegate's Office: The office of our elected Delegate, the supreme regional executive authority. Here's the place to go if you want to review any of the latest news from the executive branch, or if you wish to lodge your opinion as to just how the Delegate ought to vote on any current UN resolutions.
The Ministry of Internal Affairs:This will first and foremost be important for anyone seeking citizenship. Apply within, keeping in mind the posted requirements, and the Minister of Internal Affairs ought to process the request shortly (assuming of course that there's nothing suspicious about you).
The Office of Recruitment: It is by recruitment of course that we bring new nations into the region and keep it growing, and you too can be one yourself. Why become a recruiter? Not only does it give you the opportunity to help the region, it also is an excellent way to earn extra Tai.
The Senate: The supreme legislative authority of the region, the Senate is open to any one who has met a set of simple requirements, available in the Office of the Speaker. As a Senator, you may vote for the Delegate, Vice Delegate, Speaker of the Senate, and propose and vote on legislation.
The Laws of Taijitu: The legal code of the region, from our found Constitution to those laws passed by the Senate. If there is anything in regards to legal matters that you are unsure of, check this thread.
And of course, be sure to at the very least check out one of my personal favorites, Role Play.