Making the website 

If you are fluent in HTML you may want to hand craft your own site, but there are also dozens of free Content Management Systems (CMS)s you could use. Some have a slight learning curve and seem difficult to customize, but most offer a lot of optional features so you can usually get what you want, but possibly not exactly how you want it. Most CMSs have forum software either included or as an add on module. Forums are a great way to create new content over time. If your site will have articles you can reference them from your forum and request feedback, spawning even more relevant content. If you wont be using a CMS, then you should still consider providing forum.

Making the website findable (aka keyword optimization)

Ok, you have a basic website just waiting to be populated with content. Write an article or post  an in depth discussion sprinkling your keywords about. You'll want to use variations on the most  popular terms that relate to your topic. As an example...   

Lets pretend your site is about identity theft. What do people who are interested in identity theft type into search engines? To answer that question, visit the Overture Keyword Suggestion tool at http://inventory.overture.com/d/searchinventory/suggestion/  and enter identity theft

After posting a nice in depth article on your topic you could sign up with affiliate programs selling related products and services. You could sign up for a Google Adsense account and let them deliver relevant ads based on your site's content.