I am not asking about social book marking, am asking about social media like myspace, facebook and twitter.
I wonder how come your question hasn't got a relevant answer till now. Indeed one of the best ways for link building is by using the social media. You should try twitter and facebook to start. On twitter look for bloggers and follow them, you can message them to ask for them to follow back. Look for tweeps who follow back. Now on facebook, add the application networked blogs, and add the widget to your widget, next make a fan page for your website and make your friends like it so that it gets popular. Once you have done that check on networked blogs for other blogs to follow you and you will find other blogs very easily for link exchange. Hope my answer has been of some help.
Social bookmarking sites can go a long way to help you with link building.. They can increase your online popularity, thus bringing in more and more visitors to your website. If you want the best results, you need to enroll yourself with the top most and most popular social bookmarking sites such as Twitter, Facebook and more.
Link building is a search engine Optimization of the most important task. It is often confusing, difficult to find ideas on how to obtain construction started. Link building is the work of the other sites link to your own site. Like everything else in the world with different aspects of quality, you get high quality links shame can really hurt your own website or you can have a good relationship, which will help your rankings tremendously.