I think Link building can play a role in amplifying your exposure, which in turn brings your audience to you and builds your brand. While there are several practices floating about the web-o-sphere, there is one strategy that should be your end-all, be-all guide to link building:
Create a natural link by writing a quality, original article with a quality, relevant link in the Resource Box. Then publish the article on a well-known website.
This strategy has been the best, if not the only strategy, of hundreds of successful Expert Authors.