Google’s PageRank has always been dependent on the inter–relation of sites, pages, and links. To summarize it bluntly, links to a page determine its level of authority, in an ideal world wide web.
Checking changes in your PageRank would generally show very little variation across several weeks. You need to manage links to and from your site’s pages, and know their PR values as well. Using this visual pagerank tool, the PR of your outgoing links are displayed right in your pages — very useful for seeing how valuable are the pages you’re linking to.