You can't "list" a site in the search engine results. In other words, it's not up to you whether your site is included, and if so, where. That's up to the search engines themselves.
That said, there are some things you can do to help influence them to decide the way you'd like.
There have already been some good suggestions in this thread.
Make sure your site is user friendly, both for your human visitors and for search engine spiders. Intuitive navigation, descriptive link anchor text, logical site architecture. No coding impediments. It isn't necessary to pass W3C validation, but Google Webmaster Tools may be able to help you determine if your code is up to snuff.
Get to know your customers. Use the same words and phrases in your content that your target audience uses to describe what you're offering. If your startup is offering something new that people might not already be searching for, you're probably going to have to resort to paid advertising. Being listed in search results for a specific term doesn't help if nobody's searching for that in the first place.
Use every available means to let the world know about your startup and what you offer. Do NOT
make the mistake of relying on organic search to bring the bulk of your traffic. Develop traffic streams from social media, your blog, referral from other websites, direct (branded) traffic, etc. For safety and long-term stability, your target should be for no more than maybe about a third of your traffic from organic search. (Really.)
You may also want to take a look at the information posted by our own Debra Mastaler
and by Eric Ward
(aka "Link Moses"), who are both experts at linking strategies.
And ask lots of questions! We're here to help.