There is much to do about Link building because its one of the major factors in Google rank position algo. Without explaining Pagerank in depth, below are the things to do.

1. Focus on creating a natural incoming link structure that builds steadily but gradually over time.


2. Focus on getting links from authoritative sites with high PageRank. If they also happen to be on-topic, then all the better.


3. It's ok to get links from less important sites but remember: the lower the PageRank of a referring page, the more you'll want it to match your topic.


4. Strive to get your Inbound Links placed on pages with few outbound links... the fewer the better.


5. See to it that the URL format of your referring links are consistently identical.


6. Get your keywords into the Anchor text of your incoming links as much as possible. However, avoid identical incoming link anchor text.


7. When starting out, focus on the major directories as a source of important links then shift to the topic-specific directories to solidify the theme relevance of your site.


8. Work your trade directories, press releases, suppliers, customers, and testimonials as an outside the box approach to building a gradual, solid, lasting, and natural incoming link structure. Think creatively.


9. Don't waste a lot of time getting reciprocal links. Their value is diminishing in the current SE environment. We see a time coming when the value of reciprocal links between non-authoritative sites will be discounted or entirely cancelled out.


10. Avoid reciprocal links with pages that are designed solely for exchanging links.


11. Avoid linking back to sites that are unlisted by Google or Yahoo. Seriously avoid linking to link farms, web rings or any site that exhibits behavior contrary to a search engine's recommended protocol. Avoid linking to controversial sites unless they perfectly match the topic of your page.


12. Always remember that profits are your goal. More links does not always add more customers. Avoid wasting energy on projects that may increase link counts but add little or nothing to gain customers that generate profits.

And from last march 2005 Google Update:

1. Avoid run-of-the-site links. These are links where every page of a site links to your Homepage. When you have, say, 1000 incoming links all originating from subpages within the same site, it appears to Google that your link count is artificially inflated.


2. Make sure that some of your links are Deep links — i.e., links to sub-pages within your site and other than your homepage.


3. See to it that your incoming links from off-site pages do not include the rel="Nofollow" attribute within the source code of the link; nofollow renders the link useless to your Ranking efforts because Google doesn't credit your page for having that incoming link.

This list was first published on SE news