The first and easiest way to use Google but keep the company from collecting information on you is to use the company's services without signing in to your account. YouTube, Search and Maps don't require users to be logged in to use the services, though even signed-out users will still see ads based on their search terms, etc.
If you, like many people, are constantly signed in to your Gmail account throughout the day, things get a little more complicated.
Users can turn off the setting that allows Google to record their search history. To get to this menu, go to Google.com/history or head to the "Account Settings" menu from the top navigation bar you see when signed in to your Google account. Scroll down to the "Services" section. From here, you can pause, edit or remove all Web history. On some accounts, you can also go to the "Products" section of your account settings and click the "Edit" link next to "Your Products."
Google will still keep some of your Web history information regardless of your settings, but the results won't be used to customize your search results. According to Google, the company "also maintains a separate logs system for auditing purposes and to help us improve the quality of our services for users." Note that if you want to delete your Google Web history from your computer, you should also clear it in your browser and from any Google toolbars you may have. To do so, head to your browser's search history settings. In Firefox and Internet Explorer, you can clear history from the "Tools" menu. In Chrome, click on the wrench icon, head to the "Under the Hood" tab and choose the "Clear Browsing Data" option.
To delete all or part of your Google account (your profile, say, or your Google+ account), you can use the same "Services" area of your "Account Settings" panel.
If you don't want to delete any data but just want to start new, more privacy-friendly search habits, there are a few tips. For one, you could opt for a different search engine from time to time, which will thin out Google's data profile. You could also try using private browsing modes, which are available in each of the major browsers. Web sites you visit while using Chrome's "Incognito Mode," for example, won't show up in your browsing or download histories. Using this mode will also clear any cookies you may have picked up during your session, though changes you make to your bookmarks and general settings will stick no matter what.