Adding Google Analytic Code to site

Can anyone help? Bit of a novice with an inherited website and needing to add Google Analytics code to my site.

I have the code but unsure as to how and where to insert it. Google talks about adding to each and every post, but also an option to add into template. Would obviously like to add to the template, but unsure which template I should be adding it to, and how to do it!

Using WP 2.7.1 with a revolution lifestyle theme.

Any help greatly appreciated.