Page Rank is the measure of importance Google assigns to a Web page on a scale of 1 to 10.
You can check the PageRank value of every page you visit by downloading the Google Toolbar.

Google’s founders, Sergey Brin and Larry Page, formulated a Search Engine algorithm that shifted the ranking weight to off-page factors. They developed a formula called PageRank, in which the algorithm counts the number of sites that link to a page and then assigns the page an importance score on a scale of 1-10. The higher the number and importance of sites that link to your page, the higher the PageRank of your Web site.

What is Link Popularity?
Link Popularity refers to the number of links pointing TO your site FROM other sites on the Web.
The Search Engines consider your site more important and rank it higher if several other sites link to your site.

Quality links means links from related pages and with high rankings in search engines.
Building Quality and Relevant back links is a dual advantage where you attract vistors from the reciprocal linking site and simultaneously boost your websites Page Rank.

Types of links
There are two types of links you can establish on the web.

Reciprocal links
Link exchange is an easier way to establish links from other websites to your website.
In link exchange process, you trade links with prospective partner sites by offering a link to their site from your own site.
This method is a fast way to establish several hundred links to your website. However, it may not get you great benefits.

One-way links
To establish ‘only-incoming’ links also called ‘one-way links’ or ‘Non-Reciprocal links’.
Only incoming links are the links established on the other websites where you do not need to link back to them.

There are various compelling reasons and methods to establish such one-way links which include linking back from a different website that you may own, publishing articles on sites, content syndication, listing in trade directories and giving out press releases in news networks.

Why links are so important
Now these days, inbounds links are the one of most important factor for getting a high keyword ranking, the most search engines are ranking their search result on the link popularity from your site.
Not the quantity from the links, but the quality of those links is important.

Click here download Google Page Rank tool through you can measure Page rank of a webpage.

Google Title Length and Meta Description Length

Google shows 69 Characters (Including Spaces) for Page Title.

Google shows 156 Characters (Including Spaces) for Meta Description.

It should also be known that if you don’t include a Meta Description or if Google feels a better description for your page could be given by using a web snippet, then the description shown can be up to 320 characters. Of course, they won’t be the characters that you choose so they might not best represent what you wish your audience to see in the SERP’s.

Yahoo Title Length and Meta Description Length

Though I couldn’t find an official number from Yahoo, I have seen that

Yahoo shows up to 72 Characters (Including Spaces) for a Page Title. (PDF’s up to 75 characters).

Yahoo shows up to 161 Characters (Including Spaces) for Meta Description.

Bing Title Length and Meta Description Length

According to  the  Bing Webmaster Blog

Bing shows 65 Characters (Including Spaces) for a Page Title Tag.

Bing shows up to 150 Characters (Including Spaces) for Meta Description Tag.

Ask.com Title Length and Meta Description Length

Ask shows 69 Characters (Including Spaces) for an SEO Page Title.

I’ve never seen Ask.com use the meta description tag for it’s results. Instead it pulls a snippet of text from the page and can commonly display around 312 characters for a description.

To understand SEO you need to be aware of the architecture of search engines. They all contain the following main components:

Spider – a browser-like program that downloads web pages.

Crawler – a program that automatically follows all of the links on each web page.

Indexer – a program that analyzes web pages downloaded by the spider and the crawler.

Database– A storage for downloaded and processed pages.

Results engine – extracts search results from the database.

Web server – a server that is responsible for interaction between the user and other search engine components.

Specific implementations of search mechanisms may differ. For example, the Spider+Crawler+Indexer component group might be implemented as a single program that downloads web pages, analyzes them and then uses their links to find new resources. However, the components listed are inherent to all search engines and the seo principles are the same.

Spider. This program downloads web pages just like a web browser. The difference is that a browser displays the information presented on each page (text, graphics, etc.) while a spider does not have any visual components and works directly with the underlying HTML code of the page. You may already know that there is an option in standard web browsers to view source HTML code.
Crawler. This program finds all links on each page. Its task is to determine where the spider should go either by evaluating the links or according to a predefined list of addresses. The crawler follows these links and tries to find documents not already known to the search engine.

Indexer. This component parses each page and analyzes the various elements, such as text, headers, structural or stylistic features, special HTML tags, etc.

Database. This is the storage area for the data that the search engine downloads and analyzes. Sometimes it is called the index of the search engine.

Results Engine. The results engine ranks pages. It determines which pages best match a user’s query and in what order the pages should be listed. This is done according to the ranking algorithms of the search engine. It follows that page rank is a valuable and interesting property and any SEO specialist is most interested in it when trying to improve his site search results. In this article, we will discuss the SEO factors that influence page rank in some detail.

Web server. The search engine web server usually contains a HTML page with an input field where the user can specify the search query he or she is interested in. The web server is also responsible for displaying search results to the user in the form of an HTML page.

a.) Why does Google hate me/pick on me?

A: “Google” does not pick on individual sites but instead allows complex mathematical equations to decide the value of your site in any particular search. Although it may sometimes feel like they are picking on you, most times a ban or bad results can be traced to a small piece of bad or misguided SEO.

b.) Google banned my website?

A: You can check whether you are banned in Google or not indexed in Google, by using the ’site:’ operator in Google’s search. For instance ( site:www.yourdomain.com)

a.) What are things to look for if your site ranking goes down in Google listing? ( i.e. I have lost the top spot, what happened?)
A: Most obvious reason would be a drop in backlinks. Obviously when you are not aggressively acquiring new inbound links to your site on a day-to-day basis, existing backlinks may even deteriorate in value or The referring site may disappear, be changed, lose relevance or lose PR itself, reducing the PR that is passed onto you. Thus resulting in dip of your listing.

b.) Should I submit my website to Google every month?
A: No, you only need to do it once. In most cases you will not even need to submit your website to Google. If you are active in building links to your website then Googlebot will frequent your site soon, and thus include it in the index.