Go here and sign up for an analytics account. You will be asked for some information about your website and you fill all of it if you want all the information about your visitors. After that you will be given the JavaScript code to paste in pages that you want to track. You must paste the code in the Edit HTML window of GPC.
Google Analytics will say that the code must be pasted just before the < /body> tag. You can ignore that since you can not see that tag. Instead you can put the code anywhere in your page. What I reccomend is that you put it in the footer since it is the closest to the end of the file that we can get. If you really don't want to put it there you can put it in the subheading, since there isn't much code there and it would be simple to re-add the code if there seems to be some problems. Google analytics takes one day to process the information, so to see the visitors that you got today you must wait till tommorow. It does not have real-time updates.
You might have problems with the JavaScript since GPC does not fully support it. That is why I recommend that you paste the code somewhere that does not contain a lot of code in case that you need to re-add it, and in case that GPC blocks that part of the page for editing. If you do get some problems check out the page that tells you how I got rid of JavaScript that did not allow me to edit protions of my page.