You are actually off to a great start! Yahoo Answers offers a great place to begin promoting your website and increase your SEO (Search Engine Optimization). Not just because it allows you to post a link back to your website. But, also because if you will begin posting comments on your topic of specialization and what you offer on your website, you will then become an expert to some extent on your topic. People follow experts, thus people will begin to follow the links back to your website, consequently driving your page views, your SEO, and your Google Page Rank.
For example, my website offers the customer one website to find a great deal on some of their favorite video games. They don't need to search the internet to find a great deal on a game they want, need, or must have now. Why? Well, I do that for them, then I direct my customer to where that current great deal can be found. I search the web daily to find some of the best games for the lowest prices possible and bring that deal to the attention of my customers.
It really is that simple.
Hope this helps.