Search Engine Optimization (SEO) should be part of the design, not an afterthought.
The most successful Web site promotion follows these rules:
Have information or a product that people will be looking for.
Use good coding practices - labeling pages, using keyword phrases in the headings, text and links, and link to other Web sites relevant to your business.
Have a site that is aesthetically pleasing and easy to navigate.
Add new content and keep your material current.
Seek out reciprocal links and affiliates.
Get a Google account and take advantage of the Webmaster tools, like adding code to your index that tells Goolge "hey I'm a great site" and submitting a sitemap.
List the Web site with the Open Directory Project (DMOZ), and any other free listing.
Promote your business with local directories, like Google & Yahoo.
There is no guarantee that you will be ranked #1 in Goggle, but it's been our experience, that if you follow these rules, your ranking, and your return on investment, will be respectable.