Here is what Google says:

" PageRank relies on the uniquely democratic nature of the web by using its vast link structure as an indicator of an individual page's value. In essence, Google interprets a link from page A to page B as a vote, by page A, for page B. But, Google looks at more than the sheer volume of votes, or links a page receives; it also analyzes the page that casts the vote. Votes cast by pages that are themselves "important" weigh more heavily and help to make other pages "important."

How is PageRank calculated?

I've seen a formula for PageRank posted on Internet websites and forums but have failed to see anyone give a satisfactory explanation of the formula. The formula appears so complex you would probably have to be a mathematician to even have a chance to decipher it anyway. It looks something like this:

PR(A) = (1-d) + d(PR(t1)/C(t1) + ... + PR(tn)/C(tn))

On page optimization is the process of tuning the page for a search engine or more usually trying to make it rank highly on a selection of search engines. It's no wonder that many search engine optimization engineers focus on Google exclusively as it certainly produces the most traffic of all engines, but will that always be the case? Things can change quickly in internet land.

Description - Again, don't try to insert extra keywords here, it could backfire and your description will be edited or your listing rejected. The description should be short and concise. Just tell what your website offers and give some product or service examples if appropriate. Again, keep it short!

Be patient! - It may take weeks or months to be reviewed. If you've submitted before and are still not listed, try writing a polite note to the editor of the category to see if there was a problem.

Use common sense and careful language when asking for reciprocal links

Here are some helpful tips for requesting reciprocal links to keep in mind when you E-Mail or otherwise contact webmasters to ask to trade reciprocal links, I've have learned you usually get one shot to make a good impression. Over time I received some valuable feedback from other webmasters in assisting me on how to be requesting links, and since we are focusing on building proper links exchange channels, I would like to share this with our readers.

One final SEO factor to consider, is the difference between floating text links and links that are naturally embedded within content. Search engines understand that natural in-content links may provide more accurate anchor text, and that floating links are often used with links purchased for SEO benefit. If you can get your anchor text link from within surrounding content text, that is the ideal case.

Develop good content

There is no substitute for good content. It's content that customers look for, content that gets you up the search engine rankings and content that encourages others sites to link to yours.

But don't publish content just for the sake of having something for search engines to index. Every piece of content on your site should be there for a purpose - it must support your sales proposition and take your customers a little further along the sales cycle.