Link Building is considered by many the single most important factor in achieving high search engine rankings. If you are looking for the most cost-effective way to increase your search engine rankings, increase your page rank, and increase your website traffic, then look no further – YOU HAVE COME TO THE RIGHT PLACE!
The majority of your backlinks you acquire should:
Have a varied anchor text
Target your keywords but make very sure to vary the anchor a lot. Even a few "click here" is good to get.
Come from related pages
This is probably the most important, especially for english web sites. It is commonly believed that links from related pages carries more "weight" (not PR).