Link building is a important for achieving greater page rank in search engines. Along with quality content, search engines view inbound links as proof that your site is valuable to visitors. In other words, if lots of sites link to yours, your site must have worthwhile information, since in affect, they are citing you as an authority or a reference.
Free Directory Submissions
Directories are the logical place to start your link building campaign. They are happy to post your site to build their list or relevant results. Submit your site to as many web directories as you can. You can later refresh your information by re-submitting it, especially if content has changed. Free directories can take weeks, or even months to include your site. It is only necessary to submit your home (index) page.
Start with Google, Yahoo, MSN and the Open Directory.