Adding Google Analytics - classic Google Sites
With Google Sites you do not need to add code to your site, just the Tracking ID.
Go to Google Analytics and sign up for an account (if you have not already done so) and sign in.
Once signed in to Google Analytics you will see one of two pages dependent on whether you use Google Analytics already:
What do you want to track: if you do not use Google Analytics already you see this page, so continue to Step 3 below;
Account Home: if you already use Google Analytics you will see your Account Home page that lists your existing accounts. Go to the Admin tab and use the +New Account button and you will see the What do you want to track page.
Once you can see the What do you want to track page use the large Website button (not App) and:
in the Website name box enter your Google Site's address (e.g. www.example.com);
in the Web Site URL box enter your Google Site's address (e.g. www.example.com);
If you want to use your custom web address mapping (e.g. www.example.com) select http:// from the drop-down;
If you want to use your sites.google.com address select https:// from the drop-down;
choose a suitable Industry Category;
choose an appropriate country and time zone under
Reporting Time Zone;
In the Setting up your account section enter your Google Site's address (e.g. www.example.com) in the Account Name box;
Once you finish entering all this information use the blue
Get Tracking ID button
Google Analytics will now give your your websites Tracking ID that looks like UA-123456789-1 (yours may be longer or shorter) and you can find it highlighted in blue on the screenshot on the right.
Use the blue Save button and you're finished in Google Analytics
Return to your Google Site and now use the More button then choose Manage Site and go to the General tab
Once in the General settings check the Statistics tick box and enter the Tracking ID in the Paste your Analytics Web Property ID here: text box.
After 24 hours you should start to see data in Google Analytics.
We can offer training on how to get add Google Analytics to your Google Site and how to get the best out of Google Analytics (like the best reports to use and what to do about the statistics Google Analytics gives) via Skype or Google+ Hangout through our one-shot support service.
Further Useful tasks for your Google Site
Make you you have correctly registered your Google Site in Google Webmaster Tools, so your Google Site can get found in search engine result pages
See my Google Sites adaptation of Google's SEO Guide for more advice on how to make your website more accessible to your visitors and search engines - Google Sites - SEO (Search Engine Optimization) Guide.