Obtaining relevant and quality links from another sites is a great success in the search engine optimization process. The only important factor to consider is the page rank of linking sites and content relevancy. 

There are some strategies that must be implemented for link building to obtain search engine optimization. By following these strategies you can be sure that your site will rank above those of your competitors. 

first step is to make a content rich site to get listed easily in the search engine directories and in another relevant websites.

After making content rich site you must submit your site to all the relevant free directories, search engine directories and another relevant but not competent websites.

You must contact only to relevant sites to place your link. Thousands of links from irrelevant sites cant help you to get appropriate traffic towards your site, but some relevant links can help you to get targeted traffic to your site and help to increase your page rank.

It is very important to get links from web pages having high page rank. The most search engines like Google, Yahoo easily crawl the web pages ranked high, if you placed link on high PR pages then your targeted traffic will be increased and also help to increase your page rank. Less links on high PR pages are more useful to get traffic than more links on 0 PR pages.

Yahoo directory is paid directory and it is costly to get listed in this directory, but it is a best link on your site to get targeted traffic towards your site. Submit you site into the relevant category to your site.

Find the most relevant category to get listed in Open directory Project (ODP) It a very use full for your website. 

your links must be from the unique sites; all links must not be from one site. The incoming links should be from different IP to not being cross-referenced. If search is able to find cross-referencing then your site may be penalized.