Comment They make products for this already (Score 2, Interesting) 50
I don't know about a book. But there's products out there for using Moodle 1.9 integrated with online learning for live interactive classrooms. See Groopex Integrated Conferencing for example, which integrates Moodle with WebEx. I've already seen some language schools using this. I think that supersedes just using Moodle by itself as a language learning solution as this book describes.