A very relevant question for today's digital classroom fueled by the Internet. My colleagues and I recently published an article asking online students about what their online instructors can do to help them learn successfully. We were able to discover 10 top instructional strategies that might be helpful to you. I am also attaching some preliminary work on flexible learning environments that highlight some of the issues and trends in e-learning as well as the use of Social Media to enhance student interaction online that may also be helpful.
Data Flexible Learning Environments-Theories-Trends-Issues
Article Instructional Strategies to Help Online Students Learn: Feed...
Article Use of Facebook for enhancing student engagement in a higher...
Worth looking at is a series of UK based research reports examining issues you raise, published over past 10 years or so via jisc (used to be www.jisc.ac.uk). From Australian context, see 2 recent reports outlining methodologies and results downloadable from:
This latter website contains a variety of resources including the project bibliography, methodological details and materials produced for the Student Experience Kit.