Here’s an excellent video from the master of Link Building – Jim Boykin (@jimboykin), filmed at SES London 2010.
Jim gives an excellent overview of the risks of buying links for SEO and gives some examples of how to use great content to target worthwhile links.
Link Building – Methods and Risks with Jim Boykin @ SES London 2010 from SEOgroup on Vimeo.
Here’s links to two of the tools mentioned in the video: