Building a website is just the first step. Search engine optimization (SEO) will get your site listed in Google and other search engines. That's a good start, but marketing and promotion will bring in even more traffic.
If you own domains that you are not using you can park them and earn money. These parked domains can even earn more than fully developed domains. Sounds simple, right? It can be, but it may be hard to know how to start. I spend a lot of time helping people earn money from domain parking at parkquick.com. This site will be more free-form. I'll add stuff here that's too brief or too ephemeral to add to ParkQuick.
I'm coming at this from a different angle. I'm a domainer first. I'm learning the rest of it. I'll share a lot of what I learn - but who shares everything?