Can I turn off Google/Google+ notifications on Samsung Galaxy S3?
To turn off notifications for Google+, open the Google+ app,
press Menu->Settings->[Your account name]->Notifications, then press the ON/OFF
toggle in the top right. In recent versions, notification settings are per-account.
To turn off notifications for Gmail/Google Apps Mail, open the
Gmail app, press Menu->Settings, select the account you wish to disable notifications for, uncheck the checkbox that says: Email notifications
To turn off notifications for Google Talk, open the
Google Talk app, press Menu->Settings, select the account you wish to disable notifications for, press IM notifications and select off, and the same for Video chat notifications
To turn off notifications for Google Voice, open the
Google Voice app, press Menu->Settings->Sync and notifications, and uncheck the boxes for text and voicemail notifications.


NOTE: This is based on Android 4.0+, some of these apps (especially Google Talk) may function differently on pre-ICS.