You can monitor visitor traffic to your site with Google Analytics.
Step 1: Link a Google Analytics account to your site
To track traffic to your site, link a Universal Analytics account to your page.
Go to the Analytics site.
Click Sign up.
Complete the sign-up form.
On the Analytics profile page, copy into your clipboard -- or otherwise note -- the Analytics account number listed after your site’s name. It’ll be in the format UA-XXXXXXXX-X.
Step 2: Turn on Google Analytics tracking for your site
Open your website in Google Sites.
Click More options More actions and then Manage site.
Under "Statistics," click the drop-down menu, then click Use Universal Analytics.
In the text box under "Analytics Web Property ID," paste in the copied, or otherwise type in, the Analytics account number for your Analytics account.
At the top of the screen, click Save.
It can take up to 24 hours for Analytics to track your site. To check if your site is being tracked, go to Google Analytics and check the Home screen.