Assume a small universe of four web pages: A, B, C and D. Links from a page to itself, or multiple outbound links from one single page to another single page, are ignored. PageRank is initialized to the same value for all pages. In the original form of PageRank, the sum of PageRank over all pages was the total number of pages on the web at that time, so each page in this example would have an initial value of 1. However, later versions of PageRank, and the remainder of this section, assume a probability distribution between 0 and 1. Hence the initial value for each page in this example is 0.25.
There are two options for which ads are delivered: standard and accelerated. The standard delivery method shows ads evenly throughout the day. This option is good for advertisers who may have budget restrictions and want to ensure their ads show throughout the day. Depending on the budget concerns, ads will not show at all times. Accelerated delivery method shows ads until the budget is depleted. This option is best for advertisers who may not have budget restrictions and want to ensure their ads show for every query.
Along with the positive terms, negative keywords can be added to help remove unqualified traffic. For example, someone who searches for “free coffee table” isn’t looking to buy. By adding “free” as a negative keyword, the advertiser’s ad will not show when a query containing this term is typed. For a company selling high end products, “bargain” or “cheap” related terms may make good negative keywords.
Again, the concept is that pages cast votes for other pages. Nothing is said in the original document about pages casting votes for themselves. The idea seems to be against the concept and, also, it would be another way to manipulate the results. So, for those reasons, it is reasonable to assume that a page can’t vote for itself, and that such links are not counted.
Another excellent guide is Google’s “Search Engine Optimization Starter Guide.” This is a free PDF download that covers basic tips that Google provides to its own employees on how to get listed. You’ll find it here. Also well worth checking out is Moz’s “Beginner’s Guide To SEO,” which you’ll find here, and the SEO Success Pyramid from Small Business Search Marketing.