The Google Pagerank scheme was developed by the founders of Google, Larry Page and Sergey Brin at Stanford University. This tutorial does not go into a whole lot of theory about pagerank there is no need for that. Google isn't usually forthcoming with its technology to prevent people from manipulating their search results so nobody really knows for sure anyway. As long as you understand the basic philosophy of how pagerank works and affects your website there are things you can do and not do to harm your site so you will be ahead of the game.
Google assigns each page they index into their database a rank value from 0 to 10 , 0 is the lowest and 10 the highest. The higher rank number a page has shows that the page has a higher value than a lower rank number. A page with a 0 ranking can also be a new page with no links yet or one that has been penalized by Google for employing spam tactics in their web pages. So you want to get people with higher rank values to link to your pages.
The way it works is as other websites link to your pages they are effectively casting a vote for your page. If higher rank pages link to your page it makes your page more valuable because if higher value pages link to it then it must also be of high value. The same can be true if low rank pages link to your web pages.
To increase your pagerank you want to create such wonderful content that everyone will want to link to your page. By the way if you figure out how to do that would you drop us a note? You can also exchange links with other websites which is covered in the next paragraph.
To get a better pagerank for you web pages and website get as many inbound links from high pagerank web pages as you can, preferably web pages that aren't loaded with tons of outgoing links. Pages with tons of outgoing links on it reduces the "power" the page will have raising your page rank. The PR of that page is divided among all of the outgoing links reducing each outgoing links rank raising effectiveness. So it would be better to get a link from a PR2 page with 3 links on it than a PR4 page with 50.
That's it in a nutshell a simple explanation of how to increase the PR google page rank of your web pages. Now you can use the checker to check your pages and after you implement these tips come back to check your progress. Good Luck...