A Guide to Personalizing Learning -- rather USA-centric but very well-referenced and with some clear guidelines as to how online spaces can provide personalized learning experiences.
Research from the USA Department of Education - a meta-analysis of many studies looking at Online and Blended Learning. Mostly higher-ed focused, but still relevant points. From 2009-2010.
"Blended solutions combine contrasting learning methods and media in order to maximise effectiveness and efficiency. The More Than approach goes a step further to ensure the blend results in application to real-world tasks and the learner is supported along the whole length of their learning journey." This site includes a portfolio of resources, case studies, and video.
"Digital pedagogy calls for screwing around more than it does systematic study, and in fact screwing around is the more difficult scholarly work. Digital pedagogy is less about knowing and more a rampant process of unlearning, play, and rediscovery. We are not born digital pedagogues, nor do we have to be formally schooled in the ways of digital pedagogy. There's lots to read on the subject, but we can't just read our way into it; there is no essential canon. In fact, expert digital pedagogues learn best by forgetting - through continuous encounters with what is novel, tentative, unmastered, and unresolved."
A great resource on Blended Learning from a nonprofit think tank. Very USA-centric, but lots of ideas for how to create true blended learning environments.