Its a quite wide spectra. It depends on what you identify as your primarily target traffic. The first thing to do is to get the website as good as you can. Sit down and think about who you want to visit and then what you think these people would like to read on your site.
The best way to get traffic is through the search portals. Don’t aim to high directly, like to place top 3 for poker or casino. Instead, focus on more specific search terms and try to work your way up. Get links through directories and through exchange, read up on how to build your code and where to put the search phrase in the page.
And, don’t loose hope to fast. I have seen a lot of people open their site and give up after 1-2 months because noone is visiting. It takes time…