Preparing for Blended e-learning (Littlejohn and Pegler, Routledge 2007) provides a useful, if academic, overview of issues of blended learning, combining electronic learning with conventional classroom teaching and also the use of different forms on e-learning. With this approach some of the learning may place in a classroom, face to face, some may be online. E-learning may use audio, video, text and other media.
This book is aimed at university educators and would be particularly useful to administrators who have to cope with the issues and buzzwords involved. It will be less useful to people actually creating blended courses, as it tells what is needed to be done, but not the details of how to do it. For that "e-Learning by Design" (William Horton, 2006), is more useful.
See also: Other books on Blended Learning.