Google is a highly secretive beast. If you are trying to optimize your site to obtain high rankings, Google will provide you with little or no information. It even fails to show all of the links it is counting to your site, a negative step that no other engine takes. What Google does provide, however, is the Google PageRank for sites.
In my opinion, Google PageRank is a bit of red herring. I don't believe it tells you much about how Google views your site. Instead, it is a bit of bait designed to get you to download the Google Toolbar. Yes, you can only see your PageRank if you download a Google program on to your computer. And you thought Microsoft was bad!
Assuming you have downloaded the toolbar, the PageRank is the little bar in the middle that should be partially covered in green. The green represents your PageRank and is out of ten. You can run your cursor across it and the actual PageRank number will appear. Most sites have a PageRank of 3 to start off with. Google gives itself a rank of 10, while Yahoo and MSN each get a 9. If your bar is grey, it means you have been banned by Google for doing something they don't like in your optimization efforts. If the bar is blank, it either means your site has not been indexed yet, is relatively new or Google is updating its rankings.
So, what does the Google PageRank really mean? Not much. Originally, it was thought to be a measure of value compared to other sites. Google still touts the tool as this, but this claim appears a bit dubious. A site with a PageRank of 5 will not necessarily outrank a site with a PageRank of 3. You can perform a search on Google for practically any keyword and see as much by looking at the top 5 returned listings.
Google PageRank is an interesting tool in a very general sense. It can be used to determine that Google has found your site and how it generally values it compared to others. Just keep in mind that it does not actually mean much of anything when it comes to rankings.
