Insert Google Analytics code in your pages' header like this:
1. Edit your Typo3 root template
2. Add the following code to it (change your Google Analytics code accordingly)
// add various page metadata
page.headerData.9999 = TEXT
page.headerData.9999.value (
<script type="text/javascript">
var _gaq = _gaq || [];
_gaq.push(['_setAccount', 'UA-???????-?']);
_gaq.push(['_trackPageview']);
(function() {
var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;
ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'https://www') + '.google-analytics.com/ga.js';
var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);
})();
</script>
)