If you are looking to set your Google.com as your homepage so that whenever you open your browser you don’t need to type google.com and by default google.com will open everytime you open your browser then you need to follow below steps in your browser.
How to Set Homepage in Google Chrome
To set your favorite webpage as your home page in google chrome and have it appear whenever you start up your browser,follow instruction mention in this link.
How to Set Homepage in Firefox
Firefox is very user friendly and you can set more then one website as your home page , follow this link and learn how to set homepage in Firefox.
How to Set Homepage in Internet Explore
Learn to change your default homepage in IE ,follow this link and add google.com as your default homepage.