Google Analytics is easy to integrate to track your visitors and how they found your website. In the case of IP.Board or Invision Powered Board, integrating is very simple too.
First you will need to get your Google Analytics tracking code from your Google Analytics Admin page. If you don’t have the ‘Tracking Code’ option, it could be that you are assigned with admin permissions to your website.
Then you can go to your IP.Board’s admin, and into Look & Feel:

Under your current theme, access the dropdown menu and choose ‘Manage Templates & CSS’:

And edit the file ‘globalTemplate’:

Place your code above the </head> tag.
And that’s all. I’m writing this more for a personal note and I hope it will help you too.