I love infographics, if only to make my brain happy, and to give myself a starting point for further information digging. This is a good place to start
This was interesting... students who were heavy users of social media did not spend less time studying - so social media is neutral on grades on that point. Students who are on social media about what they are studying have slightly higher grades.
This blog makes the statement that social media helps students relate their life to their school work via social media... making school work more "active."