You can find out by downloading and installing Google's Toolbar. Click Here to download it. When you install it be sure to check "Enable Page." Once it is installed and you restart your browser, you will see a PageRank icon and green bar that shows you the rank of the web page you are currently on. If you roll the cursor over the PageRank bar it will tell you what the rank of the page is on a scale of 0 to 10.
Use the Toolbar's PageRank display to tell you how Google assesses the importance of the page you're viewing. Pages that Google believes are important receive a higher PageRank and are more likely to appear at the top of the search results. To learn more about PageRank click here.