You can find pretty much all the data that Google has on you - they allow you to examine the history of it. As far as I know they don't track your entire web browsing history but they do record all uses of their sites with your account.

But personally I certainly don't need to be logged in using any of Googles services except for GMail so I'd rather just not build up the history rather than having to go about deleting it (or not because there's so many other things to get distracted by)