You can sign in to www.Google.com website after Google Sign Up by clicking on the ‘Sign In’ button which is located at the top right corner of the web page. You will be able to sign in to your Google Account by using your Google username and password that was set up during the registration process. You will have to type your username and password in the ‘Email’ and ‘Password’ fields respectively. Then, click on ‘Sign in’ to get access to your account. You could enable the checkbox ‘Stay signed in’ if you want Google to sign in automatically when you visit the site again.