Quality Content
Having a nice clean web site design, and adding great content in the form of articles, videos, forums, newsletters, blogs and multimedia will have visitors talking about your web site and linking to your web site from their own. This is called natural linking and perhaps the most desirable type of linking that exists.

Exchanging Links
Contacting other sites like your own and exchanging links so that each site benefits from the others traffic. This may also help in achieving a higher search engine ranking for your site as well.

Directory Submission
Submitting your site to web site directories can help build traffic, Google PageRank and search enging rankings. The effectiveness the directory listing may have will depend greatly on the quality of the directory you list in.

Article Writing
Writing articles and submitting them to quality article directories will result in links back to your web site. Depending on the rules of the driectory, you may oftne place links back to your site in both the body of the article and the resource box, typically located at the bottom of the article, and the place where you make your sales pitch to the reader to click through to your site. Articles in many directories are avialable for newsletter and site publishers to download and use, gaining you another source of traffic and additional links.

Social Bookmarking
Add links to your sites in your favorite social bookmarking sites and share with friends, family, associates and others in the social bookmarking community.

Blog Comments
When posting on other personal and company blogs, be sure to leave a link back to your site whenever it is appropriate.

Forum Posting/Signature/Profile
Posting in forums is another way to bring targeted traffic back to your site. Often you can post a link in your post, as well as have a link to your site in your forum signature and profile.

Groups
Sites like Yahoo, Google and MSN all have sections for groups of users with like interests. Create your own group and join other groups that appeal to you and where it is suitable and appropriate to post a link back to your site.