It is important to keep an eye on your Page Rank. The easiest way to do this is by using a 3rd Party Tool such as SEO Quake, or PRChecker.
PR Checker
What is Pagerank, explained.
Page Rank is Googles determination of Web Page Importance, with 500 million variables and over 2 billion checks. Pages that are considered "important" are given a higher Page Ranking and hence show up higher in the search result.
PageRank also monitors the imprtance of each site by the number and Page Rank of the sites linking to it. Google puts a great deal of effort into making sure the search results give an acurate reflection of the "best of the Web"
