One of the most important and challenging factors in promoting your Web site is encouraging other Web sites to link to yours. The more sites that link to yours, especially if they have similar or related content, the more of an "authority" you become in the eyes of the search engines. However, because you have little control over other Web sites, it takes a lot of person-to-person communication to make these links happen and it takes time to establish long-term relationships with other site owners.
Tips and white hat techniques from FortyMedia.com for building inbound links:
Ensure you have a high quality Web site to which site owners can feel comfortable sending their visitors;
Create content worth linking to (articles, how-tos, games, lists, etc.);
Focus on acquiring links from sites with related content;
Avoid artificial link building and link farms (a black hat SEO technique);
Try to get listed in industry directories, association Web sites, etc.;
Create side project sites that can link to your main business Web site.
Click on "more info" below to read about Google's Link Filter.