any factors for ranking a webpage into index. Of these, the PageRank algorithm might be the best known. PageRank is probably the most discussed topic by Search Engine Optimization (SEO) experts. PageRank calculates two things: how many links there are to a web page from other pages, and the quality of the linking sites. PageRank has only ever been an approximation of the quality of a web page and doesn’t do anything such as measuring of the topical relevance of a web page. It is calculated by the link context and on-page aspects such as keyword density, title tag, and everything else.
Google mingles PageRank with complicated text-matching techniques to find how much pages are both important and relevant to user’s search query. Google examines all aspects of the page’s content (and the content of the pages linking to it) to determine if it’s a good match for user’s queries or not.
Ranking Factors (related to PageRank)
• Efficient and relevant internal onsite linking is important. Internal linking is important to your overall ranking. Make sure your linking structure is easy for the spiders to crawl and index. Most suggest a simple hierarchy with links no more than three clicks away from your home/index page.
• Anchor text is also important. The anchor text of a link is often far more significant than whether it’s on a high PageRank page. The more specific is the reference, the better Google can evaluate it and consider it in relates search queries of user.
• Google penalizes excessive linking. Google is only concerned with pages of over 100 outgoing links. Google considers overly linked pages to be link farms, and they are penalized as such.
• Headers strong tags and semantic content are vital. It doesn’t improve PageRank but decides the page relevancy. Place it in the description and meta tags, but keep your content clear and useful. Be aware of the text surrounding your keywords, search engines will become more semantic in the coming years so context is important.
• If you really want to know what are the most important, relevant pages to get links from, overlook PageRank. Think about search ranking. Search for the words you'd like to rank for. See what pages come up tops in Google. Those are the most important and relevant pages you want to seek links from. That's because Google is clearly telling you that here are the best topics you are searching for.
Google Tools & Services
• Google Quality Guidelines
Here are quality guidelines that cover the most common forms of deceptive or manipulative behavior, but Google may respond negatively to other misleading practices not listed here.
• Check if your site is in Google database
• Re-inclusion request form
Request re-inclusion of a site that has violated the webmaster guidelines
• Google Tools
A ample overview on Dmoz.org.