With the latest updates (Panda and Penguin) to the Google Search Algorithm, these appear to be the new laws:
I. Content is King
II. Links should be from independent websites
III. Don’t use an exact match keyword for every link to the same landing page
Pretty simple, right? Strive for great content (relevant and useful to those likely to find it). Put that content on great sites – nice if the blog and your content are contextually relevant. And, on occasion, use more natural language to link your content to a landing page.