Hi, How do you check your success for a single keyword of your website? do you just type it on Google and count the pages or what?
If you put a tracker on your site you can see what people search for and find your site. This way you know what keywords and terms are doing well and can make changes to increase your traffic.
I think iwebtool.com has a tool for that as well. You just put in a keyword that people would search for in the Search Engine and it will bring up where your site ranks on the SE's
Use Google Analytics or StatCounter to see where your traffic is coming from and what keywords people use to find your site. You will find your rankings for the most of your keywords in Google Webmaster Tools