Registering a Google account allows you to download and purchase content in the Google Play Store, access email through the Gmail application, receive personalized Google Search results, and have your account automatically logged in for all other Google-based services on your device.
From the home screen, tap Play Store.
Tap Existing. Note: If you need a Google account, tap 'New' and follow the on-screen prompts, or visit https://www.gmail.com.
Enter the desired Google email address and password.
Tap the Next icon.
Tap OK. Note: If Join Google+ is displayed, tap 'Not now'. To set up Google+ later, tap 'Apps' > 'Google+'.