Rand explains in this Whiteboard Friday the importance of building quality links, and what links will are important for improving SEO. He gives the following tips:
Anchor text tells the search engine what the ‘topic’ of a site is, so it’s important this is highly relevant to your website.
‘Link juice’ is the passing on of domain authority by being linked on highly respected webpages, like say that of a government department. This will pull your ranking up dramatically, even if you have very few links.
Different domains have different levels of trust and authority and Google recognises this. For example, Google gives big media outlets a lot of link authority.
Links on a diverse range of websites suggests to Google you are authoritative in some area and will improve your ranking.